Sinomenine increases osteogenesis in mice with ovariectomyinduced bone loss by modulating autophagy

BACKGROUND A decreased autophagic capacity of bone marrow mesenchymal stromal cells(BMSCs)has been suggested to be an important cause of decreased osteogenic differentiation.A pharmacological increase in autophagy of BMSCs is a potential therapeutic option to increase osteoblast viability and ameliorate osteoporosis.AIM To explore the effects of sinomenine(SIN)on the osteogenic differentiation of BMSCs and the underlying mechanisms.METHODS For in vitro experiments,BMSCs were extracted from sham-treated mice and ovariectomized mice,and the levels of autophagy markers and osteogenic differentiation were examined after treatment with the appropriate concen-trations of SIN and the autophagy inhibitor 3-methyladenine.In vivo,the therapeutic effect of SIN was verified by establishing an ovariectomy-induced mouse model and by morphological and histological assays of the mouse femur.RESULTS SIN reduced the levels of AKT and mammalian target of the rapamycin(mTOR)phosphorylation in the phosphatidylinositol 3-kinase(PI3K)/AKT/mTOR signaling pathway,inhibited mTOR activity,and increased autophagy ability of BMSCs,thereby promoting the osteogenic differentiation of BMSCs and effectively alleviating bone loss in ovariectomized mice in vivo.CONCLUSION The Chinese medicine SIN has potential for the treatment of various types of osteoporosis,bone homeostasis disorders,and autophagy-related diseases.

Effect of Ovariectomy on Serum Adiponectin Levels and Visceral Fat in Rats

This study was aimed to examine the effect of ovariectomy on visceral fat, serum adi- ponectin levels and lipid profile. Forty-five female Sprague DawIey rats were divided into three groups （n=15 each）： ovariectomized group （OVX）, ovariectomized plus estrogen-treated group （OVX＋E2）, and sham-operated group （SHAM）. Body weight, abdominal adipose tissues, serum adiponectin and lipid profile were measured and compared among the groups after three-month feeding post-surgery. Signifi- cant increases in body weight and visceral fat were found in ovariectomized rats when compared with sham-operated ones and significant increases were also observed in serum adiponectin, triglyceride and very low density lipoprotein cholesterol levels in ovariectomized rats. Body weight, visceral fat and se- rum adiponectin levels were profoundly reduced in OVX＋E2 group as compared with OVX group. It was concluded that ovarian hormone deficiency induced by ovariectomy leads to significant increases in body weight and visceral fat, along with increased serum adiponectin, triglyceride and very low density lipoprotein cholesterol levels in rats. Attenuation in these changes can be achieved by estrogen supple- mentation.

Prevention of Osteopenia and Dyslipidemia in Rats after Ovariectomy with Combined Aspirin and Low-dose Diethylstilbestrol

Objective To study whether effect of aspirin plus low-dose diethylstilbestrol is more effective and safer than high diethylstilbestrol dose alone on prevention of ovariectomy-induced osteopenia and dyslipidemia. Methods Thirty-eight 4-month-old female SD rats were divided into baseline （BAS） group （n=6）, sham operation group （n=8） and ovariectomy （OVX） group （n=24）. The OVX group was further divided into vehicle treatment group （n=8）, diethylstilbestrol （30 ug/kg.d） treatment group （OVX＋D30 group, n=8）, and aspirin （9 mg/kg.d） plus diethylstilbestrol （10 ug/kg.d） treatment group （OVX＋A-D10 group, n=8）. Their left tibiae were collected for the bone histomorphometric analysis in undecalcified sections. Left femurs were collected for the bone mineral density measurement. Results The body weight and serum cholesterol were increased, while uterine weight and cancellous bone mass were decreased in OVX rats compared with the SHAM group. Cancellous bone mass was significantly increased, while body weight and bone resorption parameters were decreased in both A-D10 and D30 treatment group compared with OVX group. The rats treated with A-D10 showed significantly increased in bone formation parameters and decreased in serum triglyceride compared with the D30-treated rats. Conclusion Aspirin plus low-dose diethylstilbestrol can effectively prevent osteopenia by reducing bone resorption, and is thus a better treatment modality for preventing dyslipidemia than high-dose diethylstilbestrol alone.

Natural orifice transluminal endoscopic surgeryvs laparoscopic ovariectomy:Complications and inflammatory response

AIM:To compare natural orifice transluminal endoscopic surgery (NOTES) vs standard laparoscopic ovariectomy in mini pigs with respect to technical aspects,complications and parameters of systemic inflammatory response.METHODS:This was a randomized,experimental,survival study.Ten female mini pigs underwent NOTES transgastric ovariectomy (NOTES group) and ten female mini pigs underwent laparoscopic ovariectomy (LAP group).A "percutaneous endoscopic gastrostomy" approach with guidewire and sphincterotome was used for gastrotomy creation.The ovary was resected using standard biopsy forceps and a snare.The access site was closed using a "KING" closure with a single endoloop and several clips.In the laparoscopic group,a three-port laparoscopy and an ovariectomy were performed with the use of standard laparoscopic devices.C-reactive protein (CRP),white blood count and interleukin (IL)-6 plasma levels were used as indicators of systemic inflammatory response.All animals were euthanized 28 d after surgery.RESULTS:All animals survived without complications.The mean procedure time was 41.3 min ± 17.6 min (NOTES group) and 25.7 min ± 5.25 min (LAP group,P < 0.02).Postmortem examinations demonstrated that 50% and 70% of animals were free of any complications in the NOTES and LAP groups,respectively.The remaining animals developed minor complications (adhesions) in a comparable frequency between the two groups.In the NOTES group,one animal developed a small intramural gastric abscess close to the gastrotomy site.A minor serous exudate that was present in 50% and 40% of the animals in the NOTES and laparoscopy groups,respectively,was not considered a complication.In both groups CRP levels increased significantly on the 2nd and 7th postoperative days (POD) and returned to normal after 28 d.On POD 2,an increase of CRP level was significantly higher in the NOTES group compared to the LAP group.Values of IL-6 did not differ from baseline values in either of the groups postoperatively.Interestingly,the platelet count decreased significantly on POD 2,but returned close to baseline values on POD 7 and PODs 28-30.CONCLUSION:Both NOTES and laparoscopic ovariectomies had a similar frequency of minor complications.However,the NOTES technique produced an increased systemic inflammatory response on POD 2.

Fourteen Days Post-Ovariectomy Estrogens Decline Is Associated with Anxiogenic Effects on Wistar Rats

On study of the effects of estrogen deficiency on anxiety disorder by using ovariectomised animals, one discrepancy was the difference in behavioral testing delay following ovariectomy and the paradigms used. Thus, the aim of this study was to evaluate the anxiogenic effects of fourteen-day estrogen decline subsequent to ovariectomy on Wistar rats using EPM （elevated plus-maze） and open field tests. As results, fourteen days of estrogens decline has induced an increase of anxiety-related behaviour by a reduction of the percentage of the number of entries into the open arm （p 〈 0.01） and an increase of the percentage of the number of entries into the closed arm （/9 〈 0.01） during the elevated plus-maze test. This anxiety-like behaviour was confirmed on the open field test by a reduction of time spent in the centre of the arena （p 〈 0.05） as well as a reduction of crossing （p 〈 0.05） and an increase of the weight of faecal boli （p 〈 0.05） and grooming （p 〈 0.01）. Meanwhile, the administration of diazepam or estradiol valerate （1 mg/kg BW each） has corrected the anxious-like behaviour in both tests paradigms. These results suggest that fourteen days of estrogens decline was associated with an anxiety-related behaviour. This experimental model can constitute an excellent tool for the study of anxiolytic substances in menopause-related anxiety.

Effect of exogenous somatotropin and staged ovariectomy on mRNA expression of select ECM-related proteins in mammary tissue of prepubertal Holstein calves

Growth hormone (GH) and estrogen are essential stimulators of mammary cell proliferation and mammary development as mammals near puberty. Mammary ductal growth requires modifications of the extracellular matrix (ECM) for this tissue expansion to occur. Our purpose was to evaluate the effects of exogenous GH and ovariectomy (known to impact estrogen production) on gene expression of selected ECM proteins in the mammary parenchyma (PAR) and mammary fat pad (MFP) of prepubertal calves. Our hypothesis was that both GH and ovariectomy would alter the mRNA expression of multiple mammary ECM proteins. However, treatment with GH significantly reduced the expression of only fibronectin in PAR. However, the mRNA expression of all of the ECM proteins tested was numerically lower in PAR from GH treated calves. In contrast, staged ovariectomy decreased expression of fibronectin and heat shock protein 90 but increased expression of epimorphin in mammary PAR. In the MFP expression of Rac-1 and fascin were increased. These findings suggest that effects of exogenous GH on mammary gland composition are only marginally dependent on alterations in ECM proteins but the more pronounced effects of ovariectomy (reduced PAR mass and altered myoepithelial ontogeny) are more likely linked to changes in expression of ECM proteins.

Lactobacillus plantarum CCFM1180 attenuates obesity induced by estrogen deficiency by activating estrogen receptor alpha in abdominal adipose tissue and regulating gut microbiota-derived metabolites

Lipid metabolism disorders commonly occur during menopause.Estrogen deficiency has been shown to lead to excessive energy intake and abnormal lipid metabolism in ovariectomized rats,resulting in obesity.Probiotics exhibit anti-obesity properties,and their underlying mechanism has been widely reported.In this study,we demonstrated the metabolic benefits of Lactobacillus plantarum CCFM1180 in suppressing appetite,controlling body weight,correcting obesity-induced abnormalities,enhancing liver lipid metabolism,and protecting liver function in estrogen-deficient rats.The mechanisms associated with the anti-obesity and anti-dyslipidemia effects of CCFM1180 on estrogen-deficient rats were clarified.The results showed that CCFM1180 dramatically reduced food intake by activating the expression of estrogen receptor alpha(ERα)and increasing the level of leptin in abdominal adipose tissue.These changes,combined with the increased butyrate concentration and recovered bile acid structure,helped enhance lipid metabolism.Additionally,CCFM1180 treatment was found to be safer than exogenous estrogen supplementation.Thus,L.plantarum CCFM1180 could be considered a new therapeutic strategy for preventing and alleviating menopausal lipid abnormalities.

Effect specificity of the early intervention with moxibustion at“BL23”in Alzheimer’s disease rats modeled by ovariectomy and D-Galactose injection

Objective:To observe the effect of the early intervention with moxibustion at "Shènshū(肾俞BL23)" on learning and memory of Alzheimer’s disease(AD) rats modeled by ovariectomy and D-Galactose(D-Gal)injection and the effect on Ca2+/CaMKII/CREB signaling pathway so as to provide the evidence for the acupoint selection in the early intervention with acupuncture and moxibustion for AD.Methods:Sixty female SD rats at the age of 3 months were selected and randomly divided into a normal group,a sham-operation group,a model group,a "BL23" group,a "Wèishū"(胃俞BL21) group,and a non-acupoint group,10 rats in each group.Except in the normal group and the sham-operation group,bilateral ovaries were removed in the other 4 groups.3 days after the operation,D-Gal was injected intraperitoneally at a dose of 150 mg/kg/d for 90 days to establish AD rat model.In the sham-operation group,only the peripheral fat of ovarian was removed and 0.9% normal saline was injected intraperitoneally of the same dose for 90 days.In the "BL23" group,the "BL21" group and the non-acupoints group,since the 2 nd day after ovariectomy,moxibustion was applied at 9:00 a.m.every day in the rats.The rats were fixed on a fixed table,the mild moxibustion with self-prepared moxa stick was applied to bilateral "BL23""BL21" and the non-acupoint of each rat,the ignited end of moxa stick was 2 cm to 3 cm far from skin surface.The infrared thermometer was adopted to measure the temperature of the epidermis of each acupoint from time to time so as to maintain the local temperature to be(41 ± 0.5)℃.Mild moxibustion lasted for 10 min each time,consecutively for 5 days a week and at an interval of 2 days.The total consecutive intervention duration was 12 weeks.In the normal group and the shamoperation group,no moxibustion intervention was performed,but the rats were restricted in a same way during the experiment.At the end of modeling and intervention,water maze test was adopted to detect the learning and memory abilities of rats in each group.The western blotting was used to detect the expressions of p-CREB,p-CaMKII,CaMKII and CREB in hippocampus of rats in each group.Results:(1)Navigation test:since Day 72,compared with the sham-operation group,the escape latencies in all of the consecutive 5 days were longer in the model group(all P <0.05).Since Day 73,compared with the normal group,the escape latency in all of the consecutive 4 days was shorter in the "BL23"group(all P <0.05).(2) Times across platform:compared with the normal group,the number of times consecutively crossing the platform was lower in the model group(P <0.05).After moxibustion,compared with the model group,the number of times across platform was higher in the "BL23"group,indicating a statistical significance(P <0.05).(3)Moving track of water maze spatial probe:the "tendency"strategy was displayed in the normal group and the sham operation group.The "marginal" strategy,which is commonly seen in the AD rats,was displayed in the model group.The "random" strategy was displayed in the "BL23" group.The "marginal" strategy was presented in the "BL21" group and the non-acupoint group.(4) Expressions of hippocampal P-CAMKII,CAMKII,CREB and P-CREB in the rats:compared with the normal group,the phosphorylation degrees of CAMKII and CREB were significantly reduced(both P<0.05) in the model group.In 12 weeks of moxibustion,compared with the model group,the levels of P-CAMKII and P-CREB were increased in the "BL23" group and the "BL21" group(all P <0.05) and the levels in the "BL23" group were higher than that of the "BL21" group and the non-acupoint group(all P<0.05).Conclusion:Moxibustion at "BL23" achieves a better effect in improving the learning and memory of AD rats modeled by ovariectomy and D-Gal injection as compared with moxibustion at "BL21" and the non-acupoint.The effect mechanism is potentially related to the effective activation of Ca2+/CaMKII/CREB signaling pathway.

The sphingosine-1-phosphate/RhoA/Rho associated kinases/myosin light chain pathway in detrusor of female rats is down-regulated in response to ovariectomy

Background:Dysuria is one of the main symptoms of genitourinary syndrome of menopause,which causes serious disruption to the normal life of peri-menopausal women.Studies have shown that it is related to decrease of detrusor contractile function,but the exact mechanism is still poorly understood.Previous results have suggested that the sphingosine-1-phosphate(S1P)pathway can regulate detrusor contraction,and this pathway is affected by estrogen in various tissues.However,how estrogen affects this pathway in the detrusor has not been investigated.In this study,we detected changes of the S1P/RhoA/Rho associated kinases(ROCK)/myosin light chain(MLC)pathway in the detrusor of ovariectomized rats in order to explore the underlying mechanism of dysuria during peri-menopause.Methods::Thirty-six female Sprague-Dawley rats were randomly divided into SHAM(sham operation),OVX(ovariectomy),and E groups(ovariectomy+estrogen),with 12 rats in each group.We obtained bladder detrusor tissues from each group and examined the mRNA and protein levels of the major components of the S1P/RhoA/ROCK/MLC pathway using quantitative real-time polymerase chain reaction and Western blotting,respectively.We also quantified the content of S1P in the detrusor using an enzyme linked immunosorbent assay.Finally,we compared results between the groups with one-way analysis of variance.Results::The components of the S1P pathway and the RhoA/ROCK/MLC pathway of the OVX group were significantly decreased,as compared with SHAM group.The percent decreases of the components in the S1P pathway were as follows:sphingosine kinase 1(mRNA:39%,protein:45%)(both P<0.05),S1P(21.73±1.09 nmol/g vs.18.86±0.69 nmol/g)(P<0.05),and S1P receptor 2/3(S1PR2/3)(mRNA:25%,27%,respectively)(P<0.05).However,the protein expression levels of S1PR2/3 and the protein and mRNA levels of SphK2 and S1PR1 did not show significant differences between groups(P>0.05).The percent decreases of the components in the RhoA/ROCK/MLC pathway were as follows:ROCK2(protein:41%,mRNA:36%)(both P<0.05),p-MYPT1(protein:54%)(P<0.05),and p-MLC20(protein:47%)(P<0.05),but there were no significant differences in the mRNA and protein levels of RhoA,ROCK1,MYPT1,and MLC20(all P>0.05).In addition,all of the above-mentioned decreases could be reversed after estrogen supplementation(E group vs.SHAM group)(all P>0.05).Conclusion::In this study,we confirmed that ovariectomy is closely associated with the down-regulation of the S1P/RhoA/ROCK/MLC pathway in the rat detrusor,which may be one mechanism of dysuria caused by decreased contractile function of the female detrusor during peri-menopause.

Impact of ovariectomy and estradiol-17β(E_(2))replacement on the brain steroid levels of the Indian stinging catfish Heteropneustes fossilis

In the present study,effects of ovariectomy(Ovx)and estradiol-17β(E2)replacement on the brain steroid levels were investigated in the resting and prespawning phases of the female catfish Heteropneustes fossilis.The study showed that Ovx resulted in significant decreases in plasma levels of estradiol-17β(E2)and its precursors,and the effect varied with the reproductive stage and duration.Our study showed that E2 supplementation reversed the effect of Ovx in 3-week Ovx fish group,either restored or increased according to the dose.In contrast,E2 levels increased in the brain after Ovx in the resting stage and produced a biphasic effect of significant decreases on week 1 and 2,and significant increases on week 3,4 and 5 in the pre-spawning stage.The brain E2 levels significantly inhibited in E2 supplementation groups.The testosterone(T)levels showed biphasic effects,an initial decrease(up to 3 weeks Ovx)and an increase later(week 4,5)in the resting stage.In the pre-spawning stage,the T levels increased significantly after Ovx.The E2 supplementation significantly inhibited the T levels,more severely in the low dose group in the resting and pre-spawning stages.Brain 17-hydroxyprogesterone(17-OHP4)levels increased(week 1,2,3)but decreased on week 4 and 5 of Ovx in the resting stage and increased throughout Ovx in the pre-spawning stage except in the 5th week(though compared to other steroids,level was very low;almost negligible).The E2 replacement significantly decreased the steroid levels further down compared to the Ovx control group.Brain progesterone(P4)and pregnenolone(P5)levels decreased initially(week 1 and 2 Ovx)and recovered later.The E2 replacement significantly decreased P4 levels in the Ovx fish in the pre-spawning stage and in the lower dose group in the resting stage.The P5 levels remained inhibited after the E2 supplementation in the resting stage but unchanged or increased it in the pre-spawning stage.Brain cortisol(F)levels were inhibited initially(1 and 2 weeks and later increased after OVX in the resting stage.In the pre-spawning stage,the F levels increased in the week 1,2 and 3 of Ovx and decreased in the 4th and 5th weeks.The E2 supplementation inhibited the cortisol(F)levels in both phases.The results show that ovarian steroids influence neurosteroidogenesis in a reproductive stage-dependent manner.

Preventive effect of Peperomia pellucida(L.) Kunth herbs on ovariectomyinduced osteoporotic rats

Osteoporosis is a metabolic skeletal disorder leading to bone fracture which adversely impacts the quality of life. In the present, we aimed to investigate the effect of Peperomia pellucida(L.) Kunth herb juice and ethanolic extract on ovariectomy(OVX)-induced osteoporotic rat model. Osteoporosis was induced by OVX with a double dorsolateral approach on female Wistar rats. Female Wistar rats undergoing sham surgeries(sham-control group) served as controls. The ovariectomized rats were divided into six groups based on administered treatments,(i) CMC Na 0.3%(OVX-control group),(ii) standard drug(ethynil estradiol 4.5 μg/kg),(iii) P. pellucida juice at dose of 50 mg/kg, and(iv) 100 mg/kg,(v) P. pellucida ethanolic extract at dose of 50 mg/kg, and(vi) 100 mg/kg. Treatments were started 1 week after the surgeries and lasted for 6 weeks. Rats treated with 100 mg/kg P. pellucida ethanol extract had significantly decreased serum ALP level and reduced excretion of urine calcium compared with the OVX-control group(P<0.05). These levels were not significantly altered when compared with the sham-control group(P<0.05). Furthermore, 100 mg/kg ethanolic extract-treated group showed improvement on three-dimensional image of the trabecular bone compared with the OVX-control group. Trabecular cavity formation in 100 mg/kg ethanolic extract-treated group was minimal. Ethanolic extract of Peperomia pellucida(L.) Kunth herbs at a dose of 100 mg/kg had preventive effect on OVX-induced osteoporotic rats.

Antifertility potential of leaves and seeds of Delonix regia in female rats

Objective:To evaluate the antifertility activity of hydroalcoholic extract of Delonix regia(Boj.ex Hook.)Raf.leaves and seeds which are traditionally being used by Yanadi tribe to treat dysmenorrhea.Methods:Three experimental animal models,including anti-implantation,early abortifacient,and estrogenic activity in female rats,were used for evaluation of the antifertility activity of both extracts at two dose levels(250 and 500 mg/kg,orally).There were five groups in the anti-implantation and early abortifacient activity while six groups in estrogenic activity including the standard.The number of implants,resorptions,vaginal cornification,body weight,uterus weight,and biochemical parameters were measured.Results:At doses 250 and 500 mg/kg,the leaf extract was found to have strong anti-implantation action.The extract administered at the same doses also caused a significant rise in the number of resorptions,showing early abortifacient activity,increased uterine weight,and altered numerous biochemical parameters.Meanwhile,the seed extract only displayed slight anti-implantation activity at both levels.Conclusions:Based on these preliminary findings,we can conclude that the leaf extract outperformed the seed extract in terms of antifertility activity,exhibiting potent estrogenic,anti-implantation and early abortifacient activities in a dose-dependent manner.These findings are consistent with the literature study and corroborate to the antifertility activity of the plant.

Updates in the pathophysiological mechanisms of Parkinson's disease: Emerging role of bone marrow mesenchymal stem cells

AIM: To explore the approaches exerted by mesenchymal stem cells (MSCs) to improve Parkinson&#x02019;s disease (PD) pathophysiology.METHODS: MSCs were harvested from bone marrow of femoral bones of male rats, grown and propagated in culture. Twenty four ovariectomized animals were classified into 3 groups: Group (1) was control, Groups (2) and (3) were subcutaneously administered with rotenone for 14 d after one month of ovariectomy for induction of PD. Then, Group (2) was left untreated, while Group (3) was treated with single intravenous dose of bone marrow derived MSCs (BM-MSCs). SRY gene was assessed by PCR in brain tissue of the female rats. Serum transforming growth factor beta-1 (TGF-&#x003b2;1), monocyte chemoattractant protein-1 (MCP-1) and brain derived neurotrophic factor (BDNF) levels were assayed by ELISA. Brain dopamine DA level was assayed fluorometrically, while brain tyrosine hydroxylase (TH) and nestin gene expression were detected by semi-quantitative real time PCR. Brain survivin expression was determined by immunohistochemical procedure. Histopathological investigation of brain tissues was also done.RESULTS: BM-MSCs were able to home at the injured brains and elicited significant decrease in serum TGF-&#x003b2;1 (489.7 &#x000b1; 13.0 vs 691.2 &#x000b1; 8.0, P &#x0003c; 0.05) and MCP-1 (89.6 &#x000b1; 2.0 vs 112.1 &#x000b1; 1.9, P &#x0003c; 0.05) levels associated with significant increase in serum BDNF (3663 &#x000b1; 17.8 vs 2905 &#x000b1; 72.9, P &#x0003c; 0.05) and brain DA (874 &#x000b1; 15.0 vs 599 &#x000b1; 9.8, P &#x0003c; 0.05) levels as well as brain TH (1.18 &#x000b1; 0.004 vs 0.54 &#x000b1; 0.009, P &#x0003c; 0.05) and nestin (1.29 &#x000b1; 0.005 vs 0.67 &#x000b1; 0.006, P &#x0003c; 0.05) genes expression levels. In addition to, producing insignificant increase in the number of positive cells for survivin (293.2 &#x000b1; 15.9 vs 271.5 &#x000b1; 15.9, P &#x0003e; 0.05) expression. Finally, the brain sections showed intact histological structure of the striatum as a result of treatment with BM-MSCs.CONCLUSION: The current study sheds light on the therapeutic potential of BM-MSCs against PD pathophysiology via multi-mechanistic actions.

Dynamics of hepatic and intestinal cholesterol and bile acid pathways: The impact of the animal model of estrogen deficiency and exercise training

Plasma cholesterol level is determined by a complex dynamics that involves transport lipoproteins which levels are tightly dependent on how the liver and the intestine regulate cholesterol and biliary acid metabolism. Regulation of cholesterol and biliary acids by the liver and the intestine is in turn coupled to a large array of enzymes and transporters that largely influence the inflow and the outflow of cholesterol and biliary acids through these organs. The activity of the key regulators of cholesterol and biliary acids may be influenced by several external factors such as pharmacological drugs and the nutritional status. In recent years, more information has been gathered about the impact of estrogens on regulation of cholesterol in the body. Exposure to high levels of estrogens has been reported to promote cholesterol gallstone formation and women are twice as likely as men to develop cholesterol gallstones. The impact of estrogen withdrawal, such as experienced by menopausal women, is therefore of importance and more information on how the absence of estrogens influence cholesterol regulation is started to come out, especially through the use of animal models. An interesting alternative to metabolic deterioration due to estrogen deficiency is exercise training. The present review is intended to summarize the present information that links key regulators of cholesterol and biliary acid pathways in liver and intestine to the absence of estrogens in an animal model and to discuss the potential role of exercise training as an alternative.

Radix Achyranthis Bidentatae improves learning and memory capabilities in ovariectomized rats

Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extracts may dose-dependently inhibit non-enzymatic saccharification in vitro. This study aimed to examine the effect of Radix Achyranthis Bidentatae on advanced glycation end products and on learning and memory capabilities in ovariectomized rats. Ovariectomized rats were treated with Radix Achyranthis Bidentatae alcohol extracts （containing 1.5 g/kg crude drug） or 0.1% aminoguanidine for 12 weeks and behavioral testing was performed with the Y-electrical maze. This test revealed that Radix Achyranthis Bidentatae and aminoguanidine could improve the learning and memory capabilities of ovariectomized rats. Results of competitive enzyme-linked immunosorbent assay showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine reduced the accumulation of advanced glycation end products in the frontal cortex of ovariectomized rats, while increasing content in the blood and urine. Biochemical tests showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine decreased superoxide dismutase activity in the serum and frontal cortex, and increased serum levels of glutathione peroxidase in ovariectomized rats. In addition there was no apparent effect on malondialdehyde levels. These experimental findings indicate that Radix Achyranthis Bidentatae inhibits production of advanced glycation end products and its accumulation in brain tissue, and improves learning and memory capabilities in ovariectomized rats. These effects may be associated with an anti-oxidative action of the extract.

Intracerebroventricular leptin injection affects neuroendocrine reproductive axis in ovariectomized rats

BACKGROUND：Leptin regulates neuroendocrine function of the hypothalamus-pituitary-ovary axis in humans. OBJECTIVE： To verify effects of intracerebroventricular leptin injection on neuroendocrine function of the hypothalamus-pituitary-ovary axis in ovariectomized rats. DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed at the Basic Medical Institute, Chengde Medical College between June and October 2007. MATERIALS： Thirty healthy, female, Wistar rats were included in this study. The following compounds were used： leptin; gonadotropin-releasing hormone （GnRH） and luteinizing hormone （LH） enzyme-linked immunosorbent assay kits. METHODS： Rats were randomly divided into 3 groups at 1, 2, and 4 hours after injection. Each group was subdivided into control and experimental groups （n = 5 animals per group and time point）. All rats were subjected to bilateral ovariectomy and, beginning on day 7 after surgery, animals received daily subcutaneous injections of estradiol benzoate （2 μg） for 7 consecutive days. The experimental groups were injected with 5 μL leptin （1 g/L） into the lateral cerebral ventricle, and control groups received an equal volume of physiological saline. MAIN OUTCOME MEASURES： GnRH and LH secretion were examined 1, 2, and 4 hours after injection using GnRH and LH ELISA kits, respectively. RESULTS： In the experimental groups, GnRH secretion significantly increased （P 〈 0.01）, followed by LH secretion （P 〈 0.01）, compared with the control groups. GnRH secretion significantly increased 1 hour after leptin injection （P 〈 0.01）. The LH increase was less pronounced, but still significant （P 〈 0.01）; however, the most prominent LH increase occurred between 1 and 2 hours. Both GnRH and LH secretion reached peak levels at 2 hours after leptin injection. Thereafter, both GnRH and LH secretion decreased, but still maintained very high levels, compared with the control group （P 〈 0.01）. CONCLUSION： Intracerebroventricular leptin injection produced similar effects on GnRH and LH secretion in ovariectomized rats, indicating regulatory effects of leptin on GnRH and LH secretion.

Isoflavone Regulates Lipid Metabolism via Expression of Related Genes in OVX Rats Fed on a High-fat Diet

Objective To investigate the effects of isoflavone on body weight, fat mass, and gene expression in relation to lipid metabolism. Methods Thirty-six female SD rats were ovariectomized or sham-operated and fed on a high-fat diet. Two months later, abdominal incision was made, blood was collected to separate serum, and the liver and adipose tissue were immediately collected and weighed. Some portions of these tissues were frozen in liquid nitrogen and stored at -80℃. Results Ovariectomy （OVX） with a high-fat diet could induce obesity in rats, while treatment with isoflavone significantly inhibited the increase in body weight and fat mass in abdomen. Serum total cholesterol and leptin were significantly decreased in isoflavone group, compared with the OVX group. The mRNA expression of liver fatty acid synthase （FAS） in the OVX group was significantly higher than that in sham-operated group, while this difference was not observed in the isoflavone group. The mRNA expression of liver hormone-sensitive lipase （HSL） in the OVX rats tended to be lower than that in the sham-operated rats. Furthermore, a large amount of isoflavone maintained the mRNA expression at a sham level. Conclusion Isoflavone may prevent obesity induced by ovariectomy with a high-fat diet, in part by modulating gene expression related to lipid metabolism.

Characteristics of Rat Lumbar Vertebral Body Bone Mineral Density and Differential Segmental Responses to Sex Hormone Deficiency:a Clinical Multidetector Computed Tomography Study

Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.

The Influence of Gonadectomy on Anxiolytic and Antidepressant Effects of Melatonin in Male and Female Wistar Rats: A Possible Implication of Sex Hormones

The main objective of this study was to analyze the effects of sex, ovariectomy (Ovx) and orchidectomy (Orx) on antidepressant and anxiolytic effect of melatonin in forced swimming test, open field test and elevated plus maze test. Initially, 4 mg/kg of melatonin was daily administered, at 4:00 pm, to intact male and female rats during 8 weeks. Our results have shown that the effect of chronic injection of Mel is sex dependent in the three behaviors tests. Females rats have responded better than males in behavior test study after administration of melatonin, this difference between the sexes may be related to the action of sex hormones (androgens and estrogens) on behavior in males as well as in females. Secondly, to determine the possible interaction between Melatonin and steroid hormones, Ovx/sham female received Mel at dose of 4mg/kg alone or NaCl (0.9%) alone, and Orx/sham male received Mel at dose of 4 mg/kg alone or NaCl (0.9%) alone daily and during 8 weeks of treatment at 4:00 pm. All animals were tested in the open-field test, elevated plus maze test for anxiety behavior study, and forced swimming test for depression behavior study. Results revealed that Mel exerts an anxiolytic and antidepressant effects in the orchidectomized males and in intact females, confirming that the suppression of androgens by orchidectomy improved anxiolytic and antidepressant effects of melatonin in males. However in females, the suppression of estrogen by ovariectomy masked the antidepressant and anxiolytic effects of melatonin. Our results confirmed that the antidepressant and anxiolytic effects of melatonin are linked to sex hormones.