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.

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.

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.

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.

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.

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.

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.

Studies of GnRH-A Active Immunization Effects on LH and FSH Secretion and Histostructure of the Ovary and Uterus in Rabbits

The objective of the study is to investigate the effects of active immunization against gonadotropin releasing hormone agonist （GnRH-A） on secretion of luteinizing hormone （LH） and follicle-stimulating hormone （FSH） in the pituitary, and to observe the histological structures and development about ovaries and uteri in female rabbits. 24 female rabbits （Oryctolagus cuniculus） were divided randomly into 4 groups （n=6）, namely, experimental group I （EG-I）, experimental II （EG-II）, experimental III （EG-III）, and control group （CG）. Rabbits were subcutaneously injected with 1.0 mL GnRH-A （alarelin） antigen respectively at concentrations of 100, 100 and 50 μg mL-1 respectively, in EG-I, EG-II and EG-III. Alarelin antigen was re-injected in EG-II and EG-III with the same dosage on 20 d. CG was a blank. The ovarian and uterine samples were collected aseptically at the end of the experiment of 70 d. The tissue slices were observed under light and electron microscopes. Serum concentrations of LH and FSH were measured with ELISA. The results showed that serum LH concentrations in EG-II and EG-III reached the peak levels on 50 and 40 d respectively, and LH level in EG-II exceeded other 3 groups on 50 d （P0.05）. FSH level in EG-II was higher than those in EG-I, CG （P0.01） and EG-III （P0.05） on 40 d. GnRH-A could increase the number of primary follicles, enlarge the primary follicle vertical diameter （PFV） and primary follicle transverse diameter （PFT）, and promote growth and maturation of follicles. The endometrial epithelium thickness （EET） and uterine wall thickness （UWT） in three EGs were less than that in CG （P0.05）. GnRH-A can increase the quantities of mitochondrial cristaes, cortex granules in cytoplasm, broaden and lengthen zona pellucidas and microvilli of oocytes. It also enlarged nuclei of ooxytes and mitochondria, thereby it promoted the development of oocytes. Re-injection of 100 μg alarelin antigen enhanced the secretion of LH and FSH. GnRH-A promoted the growth and maturation of ovaries and follicles, suppressed uterine development, and also influenced histostructure of ovaries and uteri in female rabbits.

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.

Effect of adrenalectomy on rat epididymidis

AIM: To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats. METHODS: The histological, biochemical (cholesterol protein, zinc, copper, alkaline and acid phosphatase aryl sulphatase, lactic dehydrogenase and leucine amino peptidase) and hormonal (FSH, LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed. RESULTS: Organ wet weight, histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats. Serum testosterone level was significantly lower in ADX than in sham-operated rats, while the serum FSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham-operated rats. Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated. CONCLUSION: Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone.

接受前列腺癌根治术和随后短期辅助雄激素剥夺治疗的临床局限性前列腺癌患者的睾酮恢复动力学

deprivation therapy （ADT） is a standard treatment for metastatic, recurrent and locally advanced prostate cancer （PCa）. The aim of this study is to investigate the timing and extent of testosterone recovery in clinically localized PCa patients treated with radical prostatectomy （RP） and subsequent short-term adjuvant ADT. A total of 95 localized PCa patients underwent RP and 9-month adjuvant ADT were included in this prospective study. Serum testosterone level was measured before adjuvant ADT, at ADT cessation, and at 1, 3, 6, 9 and 12 months after cessation of ADT. A Cox proportional hazards model was used to assess variables associated with the ti me of testosterone normalization. The results showed that median patient age was 67 years and median testosterone level before adjuvant ADT was 361 （230-905） ng d1-1. All patients finished 9-month adjuvant ADT and achieved castrate testosterone level. At 3 months after ADT cessation, testosterone recovered to supracastrate level in 97.9% patients and to normal level in 36.9% patients. The percentage of patients who recovered to normal testosterone level increased to 66.3%, 86.3% and 92.6% at 6, 9 and 12 months, respectively. Cox regression model found that higher baseline testosterone level （ 300 ng dl- 1） was the only variable associated with a shorter time to testosterone normalization （hazard ratio： 1.98; P -- 0.012）. In conclusion, in most patients, testosterone recovered to supracastrate level at 3 months and to normal level at 12 months after 9-month adjuvant ADT cessation. Patients with higher baseline testosterone level need shorter time of testosterone normalization.

Independent Relationship between Body Mass Index and LH Peak Value of GnRH Stimulation Test in ICPP Girls: A Cross-sectional Study

The effect of obesity on idiopathic central precocious puberty（ICPP） girls is still under discussion. The relationship between body mass index（BMI） and sexual hormone levels of gonadotropin-releasing hormone（GnRH） stimulation test in ICPP girls is controversial and the underlying mechanism is unclear. This study aims to further explore the independent effect of excess adiposity on peak luteinizing hormone（LH） level of stimulation test in ICPP girls and the role of other related factors. A retrospective cross-sectional study was performed on 618 girls diagnosed as having ICPP, including 355 cases of normal weight, 99 cases of overweight and 164 cases of obese. The results showed that obese group had more progressed Tanner stage and no significant difference（P=0.28） in LH peak was found as basal LH value was used as a covariate. The obese group had higher total testosterone（TT）, adrenocorticotrophic hormone（ACTH）, 17-α hydroxyprogesterone（17-αOHP） and androstendione（AN）, with significantly increased fasting insulin（FIN） and homeostasis model of assessment for insulin resistance index（HOMA-IR）. Stratified analysis showed inconsistency of the relationship between BMI-standard deviation score（BMI-SDS） and LH peak in different Tanner stages（P for interaction=0.017）. Further smoothing plot showed linear and non-linear relationship between BMI-SDS and LH peak in three Tanner stages. Then linear regression model was used to analyze the relationship between BMI-SDS and LH peak in different Tanner stages, with and without different confounding factors being adjusted. In B2 stage, BMI-SDS was negatively associated with LH peak. In B3 stage, when BMI-SDS 〈1.5, as BMI-SDS increased, the level of LH peak decreased（model Ⅰ： β=–1.8, 95% CI=–4.7 to 1.1, P=0.214）. When BMI-SDS ≥1.5, BMI-SDS was significantly positively associated with LH peak（model Ⅰ： β=4.5, 95% CI=1.7 to 7.4, P=0.002）. In B4 stage, when BMI-SDS 〈1.5, BMI-SDS was negatively associated with LH peak（model Ⅰ： β=–11.6, 95% CI=–22.7 to –0.5, P=0.049）. When BMI-SDS ≥1.5, BMI-SDS was positively associated with LH peak（model Ⅰ： β=–4.2, 95% CI=–3.3 to 11.7, P=0.28）. It is concluded that there is an independent correlation between BMI-SDS and LH peak of stimulation test in ICPP girls, their relationships are different in different Tanner stages, and the effect of BMI-SDS can be affected by adrenal androgens, estradiol and glucose metabolism parameters.