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Objective To explore the effect of melatonin ( MLT) on the initiation of puberty in female mice and on the expression level of phosphatidylinositol-3-kinases ( PI3K)/protein kinase B ( Akt)/mammalian target of rapamycin (mTOR) signaling pathway in the frypothalamus. Methods Seventy-eight 20-day-old female KM mice were randomly divided into melatonin (MLT) group and normal saline (NS) group, with 39 mice in each group. Starting at 22 days of age, the MLT group was given a subcutaneous injection of 1 mg/kg melatonin and the NS group was given an equal volume of saline. Thirty-two days of age were selected as the sampling point before puberty initiation and 13 mice were executed in each of the two groups, while 37 and 42 days of age were selected as the sampling point after puberty initiation and 13 mice were executed in each of the two groups. Observation of vaginal opening time in mice, weighing of ovaries and uterus to calculate organ indices. HE staining to observe the number of ovarian corpora lutea. The levels of serum luteinizing hormone (LH)were determined by ELISA. The mRNA and protein expression levels of PI3K/Akt/mTOR pathway in frypothalamus were detected by Real-time PCR and Western blotting. Results Compared with the normal saline group, mice in the melatonin group had significantly delayed vaginal opening time ( P < 0. 05 ) , decreased significantly ovarian and uterine volume and index (P<0. 05) , decreased significantly serum LH levels (P<0. 05) , and decreased significantly mRNA and protein expression levels of the frypothalamic PI3K/Akt/mTOR pathway (P<0. 05). Conclusion Melatonin delays puberty initiation in mice by a mechanism that ma)' be related to inhibition of the hypothalamic PI3K/Akt/mTOR signalling pathway.
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Aim To study the effects of Metformin (MF) on endocrine function of pituitary-gonad axis in rats. Methods The serum hormone concentration was measured with radioimmunoassay (RIA) and the morphology of gonad endocrine cells was observed with electron microscope. Results MF(135 mg?kg-1?d-1,ig,14 d)decreased serum T concentration in male rats and serum LH concentrations in female rats significantly(P
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Objective To study the variations of hypothalamus pituitary-gonad axis in Tibetan male patients with hepatic diseases and to understand the serum levels of gonadal hormone in different hepatic diseases.Methods We randomly selected 93 Tibetan male hepatic patients from Tibet Autonomous Region.The types of hepatic diseases included hepatitis A,hepatitis B,alcoholic hepatitis,cirrhosis and serious hepatitis.Meanwhile we selected 19 healthy Tibetan males as controls from the same region.We detected the serum levels of testoid (T),estradiol (E 2),follicle-stimulating hormone (FSH),luteinizing hormone (LH),prolactin (PRL) and luteinizing hormone-releasing hormone (LHRH).Statistical analysis was performed by double t-test.Results The serum levels of E 2,PRL and LHRH were all significantly different in patients with hepatic disease compared with the control.(P