N-acetylcysteine and zinc sulphate abate di-2-ethylhexyl phthalate-mediated reproductive dysfunction in rats:Focus on oxidative and sex hormone receptors mechanisms

Objective:To investigate the potential of N-acetylcysteine(NAC)and zinc sulphate(ZnSO_(4))in mitigating reproductive dysfunction caused by di-2-ethylhexyl phthalate(DEHP)in rats and to understand the underlying mechanisms,specifically oxidative stress and sex hormone receptor activity.Methods:Thirty-five male Wistar rats were randomly divided into five equal groups(n=7 per group).Group 1 was administered 0.5 mL of distilled water and served as the control group.Group 2 was given only DEHP(750 mg/kg/day),while group 3,4 and 5 were given DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day),DEHP(750 mg/kg/day)plus ZnSO_(4)(0.5 mg/kg/day),and DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day)as well as ZnSO_(4)(0.5 mg/kg/day),respectively.All treatments lasted for 21 days.Samples were obtained after the rats were sacrificed,and hormones levels in the serum and markers of oxidative stress in the testicles were analyzed using the enzyme-linked immunosorbent assay.The amount of androgen receptors in the testicles was determined by immunohistochemistry,and the susceptibility of testosterone and DEHP to bind to androgen receptor and 5α-reductase was determined by molecular docking studies.Results:DEHP decreased reproductive hormones,testicular antioxidant enzymes,increased malondialdehyde levels,and negatively impacted histology of the pituitary and testes.NAC or ZnSO_(4) treatment showed a marked improvement in testicular antioxidant status and hormone levels,as well as a positive effect on the histology of the pituitary and testes.The combination of both treatments appeared to be more effective.The affinity of DEHP to bind to androgen receptors may lead to disruption of androgen receptor signaling,which can further result in dysfunction of hormones related to androgen.However,NAC is more likely to form stronger binding interactions with follicle stimulating hormone and luteinizing hormone receptors,as well as gonadotropin-releasing hormone receptors,when compared to DEHP.Conclusions:The possibility that NAC and ZnSO_(4) could downregulate DEHP-induced sex hormone changes is suggested by their potential to reduce toxicity.

Influence of leptin on luteinizing hormone and follicle stimulating hormone secreted from cultured rat anterior pituitary cells

BACKGROUND： Leptin may regulate reproductive function via release of hypothalamic neuropeptide Y. However, it is unknown whether this regulatory effect is limited to the hypothalamus. OBJECTIVE： To detect the effect of different dosages of leptin on luteinizing hormone （LH） and follicle stimulating hormone （FSH） secretion from in vitro cultured rat anterior pituitary cells. DESIGN： Contrast study based on cells. SETTING： This study was performed in the Basic Institute of Chengde Medical College, Chengde City, Hebei Province, China from March to June 2007. MATERIALS： Eighteen female Wistar rats of three months of age, weighing 200-220 g, and of clean grade were used. Leptin was provided by Peprotech Company, DMEM culture medium by Invitrogen Company, and the radioimmunological kit by Beijing Zhongshan Jinqiao Biotechnology Co., Ltd. METHODS： Three glandular organs were regarded as one group for culture of anterior pituitary cells. In the control group, saline was added to the culture medium instead of leptin. In the leptin group, leptin was prepared into different concentrations of 1×10^-12, 1×10^-11, 1×10^-9, 1×10^-7, and 1×10^-6 mol/L for stimulation of cultured cells. The culture supernatant was obtained at three hours after additional of saline/leptin. MAIN OUTCOME MEASURES： Contents of LH and FSH were detected by radioimmunology. RESULTS： Following leptin stimulation, LH release increased with increasing concentrations of leptin up to 1×10^-9 mol/L, where LH release peaked. LH release then progressively decreased with increasing leptin concentrations （P 〈 0.01）. LH release in the leptin （1×10^-12, 1×10^-11, 1×10^-7, and 1×10^-6 mol/L） groups was significantly higher than that in the control group （P 〈 0.01）. FSH content in the leptin （1×10^-11, 1×10^-9, and 1×10^-7 mol/L） groups was significantly higher than that in the control group （P 〈 0.01）. CONCLUSION： Leptin can directly affect pituitary tissue to promote the secretion of LH and FSH in a dose-dependent manner.

Beneficial effects of a decreased meal frequency on nutrient utilization,secretion of luteinizing hormones and ovarian follicular development in gilts

Background:Replacement gilts are typically fed ad libitum,whereas emerging evidence from human and rodent studies has revealed that time-restricted access to food has health benefits.The objective of this study was to investigate the effect of meal frequency on the metabolic status and ovarian follicular development in gilts.Methods:A total of 36 gilts(Landrace×Yorkshire)with an age of 150±3 d and a body weight of 77.6±3.8 kg were randomly allocated into one of three groups(n=12 in each group),and based on the group allocation,the gilts were fed at a frequency of one meal(T1),two meals(T2),or six meals per day(T6)for 14 consecutive weeks.The effects of the meal frequency on growth preference,nutrient utilization,short-chain fatty acid production by gut microbial,the post-meal dynamics in the metabolic status,reproductive hormone secretions,and ovarian follicular development in the gilts were measured.Results:The gilts in the T1 group presented a higher average daily gain(+48 g/d,P<0.05)and a higher body weight(+4.9 kg,P<0.05)than those in the T6 group.The meal frequency had no effect on the apparent digestibility of dry matter,crude protein,ether extract,ash,and gross energy,with the exception that the T1 gilts exhibited a greater NDF digestibility than the T6 gilts(P<0.05).The nitrogen balance analysis revealed that the T1 gilts presented decreased urine excretion of nitrogen(−8.17 g/d,P<0.05)and higher nitrogen retention(+9.81 g/d,P<0.05),and thus exhibited higher nitrogen utilization than the T6 gilts.The time-course dynamics of glucose,α-amino nitrogen,urea,lactate,and insulin levels in serum revealed that the T1 group exhibited higher utilization of nutrients after a meal than the T2 or T6 gilts.The T1 gilts also had a higher acetate content and SCFAs in feces than the T6 gilts(P<0.05).The age,body weight and backfat thickness of the gilts at first estrous expression were not affected by the meal frequency,but the gilts in the T1 group had higher levels of serum luteinizing hormone on the 18th day of the 3rd estrus cycle and 17β-estradiol,a larger number of growing follicles and corpora lutea,and higher mRNA expression levels of genes related to follicular development on the 19th day of the 3rd estrus cycle.Conclusions:The current findings revealed the benefits of a lower meal frequency equal feed intake on nutrient utilization and reproductive function in replacement gilts,and thus provide new insights into the nutritional strategy for replacement gilts,and the dietary pattern for other mammals,such as humans.

Long-term effectiveness of luteinizing hormone-releasing hormone agonist or antiandrogen monotherapy in elderly men with localizect prostate cancer （T1-2） ： a retrospective study

Aim： To evaluate the long-term effectiveness, side effects and compliance rates of two types of drugs （luteinizing hormone-releasing hormone [LHRH] agonist and antiandrogen） that were used individually to treat patients with localized prostate cancer （T1-2） at our institution. Methods： Ninety-seven patients who were diagnosed in the period from April 1997 to January 2000 as having clinically localized prostate cancer （T1-2） received either LHRH agonist （leuprolide acetate 7.5 mg/month） monotherapy （group 1, n = 62） or antiandrogen monotherapy （group 2, n = 35; 18 received bicalutamide 50 mg q.d., 13 received nilutamide 150 mg t.i.d, and 4 received flutamide 250 mg t.i.d.）. The mean age in both groups was 76 years. Results： The mean follow-up time was （50.8 ±8.5） months in group 1 and （43.1 ± 2.2） months in group 2. Prostate-specific antigen （PSA） levels rose in only 1 of the 62 patients （1.6%） in group 1, and in 20 of the 35 patients （57.1%） in group 2. In group 2, 10 of the 20 patients （50 %） with increasing PSA levels were treated with LHRH salvage therapy, and eight （80%） responded. Hot flashes （54.8%） and lethargy （41.9%） were the most common side effects in group 1. In contrast, nipple-tenderness （40%） and light-dark adaptation （17.1%） were more often seen in group 2. Only 1 of the 62 patients （1.6%） in group 1 switched to another medication because of adverse side effects; whereas 8 of the 35 patients （22.9%） in group 2 did so. Conclusion： Unlike antiandrogen monotherapy, LHRH agonist monotherapy provided long-term durable control of localized prostate cancer （T1-2）. It can also be an effective treatment option for patients whose disease failed to respond to antiandrogen monotherapy. The limitations of our study are the lack of health outcomes analysis and a small sample size.

Effect of Luteinizing Hormone-Releasing Hormone Analogue on the Sexual Behavior of Sacalia quadriocellata

Luteinizing hormone-releasing hormone(LHRH) is known to influence sexual behavior in many vertebrate taxa, but there have been no systematic studies on the role of LHRH in sexual behavior of turtles. We tested the hypotheses that exogenous LHRH analogues would induce sexual behavior of male Four-eyed turtle, Sacalia quadriocellata. We examined this by challenging males with intramuscular injections of mammalian luteinizing hormone-releasing hormone analogue(LHRH-A), human chorionic gonadotropin(HCG), or a combination of the two, and subsequently exposing them to sexually receptive females for behavioral observation. Our data show that the injection of only HCG could not, while that of only LHRH-A could, facilitate sexual behavior along with testicular recrudescence and spermatogenesis in S. quadriocellata. The injection of both LHRH-A and HCG would induce more drastic sexual behavior of the animals than that of LHRH-A alone, indicating HCG enhances the effects of LHRH-A induced sexual behavior. However, different pharmacological dosages of LHRH-A(0.5 μg, 1 μg, 2 μg per 100 g bodyweight) did not correspond to different activity levels. Though the mechanism of LHRH effect was not determined, this study may support that the sexual behavior of S. quadriocellata which occurs at the beginning of the injection despite regression of the gonads. This is the first report on the exogenous LHRH-A induced sexual behavior for this species.

Immunohistochemical observation on luteinizing hormone in rat testes before and after testicular capsulotomy

Aim: In the testicular capsulotomized rats, although there was a significant increase in the luteinizing hormone (LH)levels, the secretion of testosterone remained low. In order to clarify the mechanisms of this phenomenon, the bindingof endogenous LH to the testes were observed before and after testicular capsulotomy. Methods; Peroxidase-anti-peroxidase (PAP) method was used to detect the binding of LH to the testes in rats. Results; An intense positivestaining of LH was found in the Leydig cells of both the normal and sham-operated control testes. However, at 40 d af-ter operation, the LH immunoreactivity was decreased in the Leydig cells of the capsulotomized testis. By d 60, onlyvery weak positive staining could be observed in these cells. Conclusion; A progressive reduction of endogenousLH binding to the testis occurred in the capsulotomized rat. (Asian J Androl 2001 Sep; 3 : 227 - 230)

Plasma levels of luteinizing hormone and prolactin in relation to double brooding in Great Tit(Parus major)

The reproductive behaviors of birds are mainly controlled by the hypothalamus-pituitary-gonad axis.Many studies have shown that reproductive hormones are tightly linked to the breeding sub-stages.However,only a few studies have examined the temporal trend of hormone levels among different reproductive stages in multiple brooded species.We investigated the changes in plasma luteinizing hormone(LH)and prolactin(PRL)concentrations during different reproductive stages of the facultative double-brooded Great Tit(Parus major).We found that the concentrations of LH and PRL in females were significantly higher than those in males.Females had significantly higher LH and lower PRL concentrations in the pre-breeding period than in the first/second brooding periods,and there were no significant changes between the first and second brooding periods.The concentrations of LH and PRL in males had no significant difference between the pre-breeding period and the first brooding periods,while LH and PRL concentrations in the second brooding period were significantly higher than those in the first brooding period.We conclude that there are sex-based differences between LH and PRL at different stages of reproduction.The changes in LH and PRL in both males and females should be related to their physiological functions.Especially for males,individuals with higher levels of LH and PRL are more likely to maintain second clutches.

Effect of Kisspeptin on Regulation of Growth Hormone and Luteinizing Hormone in Lactating Dairy Cows

Kisspeptin （KP） , a neuroendocrine regulator of reproduction,is hypothesized to be an integrator of metabolism and hormones critical to the regulation of reproduction. Lactation is associated with enhanced growth hormone （GH） responsiveness and reduced fertility. Our study was designed to determine the effects of lactation on KP-stimulated GH and luteinizing hormone （LH） secretion. Five non-lactating and five lactating dairy cows were used in the study. Experiments were conducted with lactating cows at weeks 1,5 and 11 after parturition. The experimental treatments （saline and KP [100 and 400 pmol / kg body weight]） were given intravenously and blood was collected and plasma was stored until later assay to determine concentrations of GH,LH,progesterone and nonesterified fatty acids. We found that neither dose of KP stimulated an increase in GH secretion. The low dose ofKP increased （P 〈0. 05） LH concentrations only in lactating cows. The higher dose of KP elicited an increase in circulating LH concentrations in both lactating and non-lactating cows. The lower dose of KP increased （P 〈 0. 05） the area under the curve for LH only in cows during week 5 of lactation,and the area under the curve of LH following the highest dose of KP was greater （P 〈 0. 05） in cows during week 5 of lactation than that for the other groups of cows. In summary,lactation status and stage of lactation did not change the sensitivity of the GH system to KP. However,an effect of stage of lactation on KP-stimulated LH secretion was detected in the dairy cows. Study of the KP system during lactation in dairy cows may provide critical insights into the mechanisms for lactation-associated changes in the reproductive axis.

Association between luteinizing hormone level decrease on the triggering day and pregnancy outcome for in vitro fertilization/intracytoplasmic sperm injection patients following gonadotropin-releasing hormone antagonist protocol: a retrospective cohor

Objective:Optimal luteinizing hormone(LH)levels forin vitro fertilization/intracytoplasmic sperm injection(IVF/ICSI)patients following the gonadotropin-releasing hormone(GnRH)antagonist protocol remain controversial.This study aimed to estimate the association between serum LH levels on the triggering day(LHLOT)and clinical pregnancy outcomes in IVF/ICSI patients following the GnRH antagonist protocol.Methods:We enrolled 4743 IVF/ICSI cycles using flexible or fixed GnRH antagonist protocols between January 2017 and June 2021.The patients were stratified into four groups according to the LHLOT quartiles(Q1–Q4).Each group was further divided into two subgroups according to the median basal LH/LHLOT.The main outcomes were clinical pregnancy,birth,and miscarriage rates.Secondary outcomes were oocyte yield,number of MII,fertilized oocytes(2PN),and high-quality embryos.Results:Serum LHLOT levels were negatively correlated with oocyte yield and the numbers of MII,2PN,and high-quality embryos.Reproductive outcomes were compared among the different quartiles and subgroups.The absolute difference in the clinical pregnancy rates between the Q4 and Q1 groups was 6.4%(47.2%vs.40.8%,P<0.05).Clinical pregnancy rates between the subgroups with basal LH/LHLOT>3.04 and≤3.04 were 32.7%and 48.6%(P<0.01),respectively,in Q1.Within Q3,the clinical pregnancy rates between the subgroups with basal LH/LHLOT>2.14 and≤2.14 were 50.2%and 41.9%,respectively(P<0.05).The greater the decrease in LH levels,the lower the oocyte maturation rate across all quartiles.Conclusions:According to the LHLOT quartiles,the Q1 of serum LHLOT<1.43 IU/L may result in a higher number of oocytes but reduced oocyte maturation and lower clinical pregnancy rates.A decrease in LH levels by approximately 2.14 to 3.04 times compared to basal LH levels may lead to higher clinical pregnancy rates in IVF/ICSI patients following the GnRH antagonist protocol.

Effects of Environmental Lead Pollution on Blood Lead and Sex Hormone Levels among Occupationally Exposed Group in An E-waste Dismantling Area

Objective To study the effects of environmental multi-media lead pollution on blood lead and sex hormone levels among lead exposed males engaged in E-waste dismantling, and the correlation between confounding factors and sex hormone levels. Methods An E-waste dismantling area in Taizhou of Zhejiang Province was selected as the research site. One hundred and fifty two samples were collected from the groundwater, soil, rice, corn, chicken, and pork in the dismantling area. The effects of the multi-media lead pollution on the male blood lead and sex hormone levels of FSH, LH, and T, as well as the correlation with confounding factors, were studied. Results The blood lead concentrations in the males aged under 31, from 31 to 45 and from 46 to 60 were 98.55, 100.23, and 101.45 I~/L, respectively. Of all the environmental media lead exposures, the groundwater, rice and soil were main contributing factors to the lead accumulation in humans. FSH and LH levels increased with the age while the T levels decreased with the age instead. There was a significant correlation between the FSH and LH levels and wearing masks. Conclusion There was correlation between the FSH, LH, and T levels, and the mean values of lead concentrations in environmental media, and the sex hormone levels were correlated with the confounding factor of wearing masks.

The Effects of Lei Gong Teng on Reproductive Hormones

The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii Wilfordii). The results showed that Lei Gong Teng could induce amenorrhea, but it was reversible.

Androgen receptor gene polymorphism and sex hormones in elderly men:the Tromsøstudy

The aim of this study was to examine whether CAG/GGN repeats are significant modulators of serum concentrations of total and free testosterone(T)as well as of luteinizing hormone(LH)in elderly men.Sixty-nine 60-to 80-year-old men with subnormal T levels(≤11.0 nmol L^(-1))and 104 men with normal T levels taking part in a nested case-control study were used for these analyses.Sex hormones were measured and free T was calculated.The CAG and GGN polymorphisms in the androgen receptor gene were determined by polymerase chain reaction and subsequent direct sequencing.There were no differences in the CAG and GGN repeat lengths between the groups.In cross-sectional analyses of the whole cohort,total and free T were positively associated with CAG length(all P<0.05)before,but not after,waist circumference or body mass index was added to the model.CAG repeat lengths were weakly,but not independently,associated with total and free T.These findings indicate that when clinically evaluating T and LH levels in elderly men,the CAG and GGN repeat lengths do not need to be taken into consideration.

Morphological changes of gonadotropin-releasing hormone neurons in the rat preoptic area across puberty

Gonadotropin-releasing hormone （GnRH） neurons in the preoptic area may undergo morphological changes during the pubertal period when their activities are upregulated. To clarify the regulatory mechanism of puberty onset, this study aimed to investigate the morphological changes of GnRH neurons in the preoptic area of GnRH-enhanced green fluorescent protein transgenic rats. Under confocal laser microscopy, pubertal GnRH neurons exhibited an inverted Y distribution pattern. Prepubertal GnRH neurons were generally unipolar and bipolar, and were distinguished as smooth type cells with few small processes or irregular type cells with many spine-like processes in the proximal dendrites. The number of GnRH neurons in the preoptic area and spine-like processes were increased during the course of reproductive maturation. There was no significant difference between male and female rats. Immunofluorescence staining revealed synaptophysin punctae close to the distal end of GnRH neurons, indicating that some presynaptic terminals may form a synaptic linkage with these neurons.

Kisspeptin regulates gonadotropin-releasing hormone secretion in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats

Kisspeptin is essential for activation of the hypothalamo-pituitary-gonadal axis. In this study, we established gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. Rats were injected with 1, 10, or 100 pM kisspeptin-10, a peptide derived from full-length kisspeptin, into the arcuate nucleus and medial preoptic area, and with the kJsspeptJn antagonist peptJde 234 into the lateral cerebral ventricle. The results of immunohistochemical staining revealed that pulsatile luteinizing hormone secretion was suppressed after injection of antagonist peptide 234 into the lateral cerebral ventricle, and a significant increase in luteinizing hormone level was observed after kisspeptin-10 injection into the arcuate nucleus and medial preoptic area. The results of an enzyme-linked immunosorbent assay showed that luteinizing hormone levels during the first hour of kisspeptin-10 infusion into the arcuate nucleus were significantly greater in the 100 pM kisspeptin-10 group than in the 10 pM kisspeptin-10 group. These findings indicate that kisspeptin directly promotes gonadotropin-releasing hormone secretion and luteinizing hormone release in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. The arcuate nucleus is a key component of the kisspeptin-G protein-coupled receptor 54 signaling pathway underlying regulating luteinizing hormone pulse secretion.

Real-world effectiveness and safety of goserelin 10.8-mg depot in Chinese patients with localized or locally advanced prostate cancer

Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of the LHRH agonist,goserelin,particularly the long-acting 10.8-mg depot formulation,and the follow-up patterns among Chinese prostate cancer patients.Methods:This was a multicenter,prospective,observational study in hormone treatment-na?ve patients with localized or locally advanced prostate cancer who were prescribed goserelin 10.8-mg depot every 12 weeks or 3.6-mg depot every 4 weeks with or without an anti-androgen.The patients had follow-up evaluations for 26 weeks.The primary outcome was the effectiveness of goserelin in reducing serum testosterone and prostate-specific antigen(PSA)levels.The secondary outcomes included testosterone and PSA levels,attainment of chemical castration(serum testosterone<50 ng/d L),and goserelin safety.The exploratory outcome was the monitoring pattern for serum testosterone and PSA.All analyses were descriptive.Results:Between September 2017 and December 2019,a total of 294 eligible patients received≥1 dose of goserelin;287 patients(97.6%)were treated with goserelin 10.8-mg depot.At week 24±2,the changes from baseline[standard deviation(95%confidence interval)]in serum testosterone(n=99)and PSA(n=131)were-401.0 ng/d L[308.4 ng/d L(-462.5,-339.5 ng/d L)]and-35.4 ng/m L[104.4 ng/m L(-53.5,-17.4 ng/m L)],respectively.Of 112 evaluable patients,100(90.2%)achieved a serum testosterone level<50 ng/d L.Treatment-emergent adverse events(TEAEs)and severe TEAEs occurred in 37.1%and 10.2%of patients,respectively.The mean testing frequency(standard deviation)was 1.6(1.5)for testosterone and 2.2(1.6)for PSA.Conclusions:Goserelin 10.8-mg depot effectively achieved and maintained castration and was well-tolerated in Chinese patients with localized and locally advanced prostate cancer.

EFFECTS OF DOPAMINE,ESTRADIOL AND TESTOSTERONE ON GONADOTROPIN RELEASE FROM THE PITUITARY FRAGMENTS OF Rana rugulosa

To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).

Improved sexual behavior in male rats treated with a Chinese herbal extract： hormonal and neuronal implications

Aim： To investigate the influence of an extract obtained from five Chinese medicinal plants on sexual behavior of adult male rats. Methods： The extract was administered at doses of 30, 60 and 120 mg/kg by oral gavage, acutely （one time, 45 min before mating test） or subchronically （daily for 10 days） in sexually potent and sexually sluggish/impotent rats. Sexual behavior, serum levels of luteinizing hormone （LH） and testosterone （T） were evaluated in treated rats and compared with controls receiving vehicle. The effect of the extract on central dopaminergic neurotransmission was assessed in the nucleus accumbens using a microdialysis technique. Results： In sexually potent rats, both acute and subchronic treatment with the extract dosed at 30 and 60 mg/kg reduced mount latency and intromission latency. In sluggish/impotent rats, the acutely administered extract at the dose of 60 mg/kg shortened ejaculation latency, whereas subchronically administered at the doses of 30 and 60 mg/kg, reduced mount, intromission and ejaculation latencies, increasing also the percentage of mounting and ejaculating rats. The extract dosed at 60 mg/kg significantly increased LH and T following acute and subchronic administration and increased 3,4-dihydroxyphenylacetic acid levels in the nucleus accumbens, 30 min after the acute administration. Conclusion： The improvement in both appetitive and consummatory components of sexual behavior observed in male rats treated with the extract could be ascribed to increased serum T level in parallel with the activation of the central dopaminergic system.

The inhibitory effects on adult male reproductive functions of crude garlic （Allium sativum） feeding

Aim： To investigate the effects of crude garlic on adult male rat reproductive functions. Methods： Thirty male rats were divided into five groups： group 1 （untreated） and groups 2, 3, 4 and 5 were fed for 30 days with 5%, 10%, 15% and 30% crude garlic, respectively. Testes and accessory organs were weighed and some markers were assessed. Light and electron microscopy observations were also performed. Results： A significant decrease was observed in the body weight of groups 4 （14%; P 〈 0.01） and 5 （20%; P 〈 0.01）; of the prostate weight in group 5 （29.1%; P 〈 0.05） and of seminal vesicle weight in groups 3 （14.4%; P 〈 0.01）, 4 （18.3%; P 〈 0.01） and 5 （27.3%; P 〈 0.01）. In contrast, testis and epididymis weights were unchanged. In epididymis tissue, the alpha glucosidase activity and the spermatozoa density were unchanged. The treatment resulted in a significant decrease in testosterone serum levels in groups 3 （77.3%; P 〈 0.01）, 4 （77.3%; P 〈 0.01） and 5 （90.9%; P 〈 0.01）, associated with a significant increase in LH serum levels （P 〈 0.01）. Testicular histology showed a dose-dependent increase in the percentage of empty seminiferous tubules. Moreover, testicular function was affected; a significant decrease in phosphatase acid activity （P 〈 0.01） and testosterone （P 〈 0.05） contents were observed. Conclusion： Crude garlic consumption during 1 month reduced testosterone secretion and altered spermatogenesis at 10%, 15% and 30% doses.

nfluence of paradoxical sleep deprivation and sleep recovery on testosterone level in rats of different ages

This study was performed to assess serum testosterone alterations induced by paradoxical sleep deprivation （PSD） and to verify their attenuation during sleep recovery （SR） based on different durations and ages. Wistar male rats aged 12 weeks for the younger group and 20 weeks for the elder group were randomly distributed into one of the following groups： a control group （cage and platform）, 3-day SD, 5-day SD, 7-day SD, 1-day SR, 3-day SR and 5-day SR groups. For PSD, the modified multiple platform method was used to specifically limit rapid eye movement （REM） sleep. Differences in the testosterone and luteinizing hormone levels between the younger group and the elder group according to duration of PSD and SR recovery were analysed. Testosterone continued to fall during the sleep deprivation period in a time-dependent manner in both the younger （P=-0.001, correlation coefficient r=-0.651） and elder groups （P=0.001, correlation coefficient r=-0.840）. The elder group showed a significantly lower level of testosterone compared with the younger group after PSD. Upon SR after 3 days of PSD, the testosterone level continued to rise for 5 days after sleep recovery in the younger group （P=0.013）, whereas testosterone concentrations failed to recover until day 5 in the elder group. PSD caused a more detrimental effect on serum testosterone in the elder group compared to the younger group with respect to decreases in luteinizing hormone （LH） levels. The replenishment of serum testosterone level was prohibited in the elder group suggesting that the effects of SD/SR may be age-dependent. The mechanism by which SD affects serum testosterone and how age may modify the process are still unclear.

Regulative Actions of the Chinese Drugs for Tonifying the Kidney on Gene Expression of the Hypothalamic GnRH,Pituitary FSH,LH and Osteoblastic BGP

It is found that the drugs for nourishing yin to reduce pathogenic fire can significantly down-regulate,and the drugs for tonifying the kidney to replenish essence can up-regulate mRNA expression of the hypothalamic GnRH,pituitary FSH,LH and osteoblastic BGP,indicating that the Chinese drugs for tonifying the kidney can regulate gene expression of the hypothalamic GnRH,pituitary FSH,LH,and osteoblastic BGP,which is possibly one of the main mechanisms of the Chinese drug for tonifying the kidney,regulating ephebic development process and improving skeletal development in sexual precocity children.