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[ABSTRACT]AIM:Toexploretheroleofkisspeptin/GPR54signalingpathwayinthepathogenesisofprecocious puberty based on female precocious puberty rat model induced by the single dose of danazol .METHODS:Female SD rats aged 3 d were randomly divided into normal group , vehicle group and model group .On the 5th day, the model rats were given a single subcutaneous injection of danazol with ethanol and ethylene glycol mixture .All rats were executed on 15 d, 25 d, 30 d, 35 d and 40 d, and the samples were collected to observe the sexual organ development .The levels of E2 , FSH and LH in peripheral blood were measured by ELISA .The Kiss-1 mRNA expression of Kiss-1, GPR54 and GnRH in hypothalamus was detected by real-time PCR.The kisspeptin expression in rat hypothalamus was observed by immunofluo-rescence .RESULTS:The time for puberty onset and sexual maturation in the model rats was significantly earlier than that in normal group and vehicle group .On days 25 and 30, the levels of peripheral sex hormones and uterine coefficients in model group were significantly higher than those in normal group and vehicle group .On days 25 and 30, the ovarian mor-phological development in the model rats was significantly earlier than that in normal group .On day 25, the mRNA expres-sion of hypothalamic Kiss-1 and GnRH, and kisspeptin expression of hypothalamic arcuate nucleus in the model rats signifi -cantly increased compared with normal group and vehicle group .On day 30, kisspeptin expression of hypothalamic arcuate nucleus in the model rats decreased compared with normal group and vehicle group .On day 35, the mRNA expression of Kiss-1 and GnRH in the model rats decreased compared with normal group and vehicle group .The mRNA expression of GPR54 had no obvious difference among all groups .CONCLUSION:The Kiss-1 mRNA and kisspeptin expression in the model rats with precocious puberty is significantly increased in the hypothalamus during onset of puberty , suggesting that kisspeptin is an initiating factor for precocious puberty .Kisspeptin/GPR54 signaling pathway may play an important role in the occurrence of precocious puberty .
ABSTRACT
Objective To observe the effects of electroacupunture (EA) on the abnormal hypothalamus-pituitary-adrenal (HPA) axis and the expression of hypothalamic corticotropin-releasing factor (CRF) peptides family and CRF receptor (R)1 mRNA in traumatized rats,so as to study its underlying mechanism in improving traumatic injury. Methods Forty male Sprague-Dawley rats were randomly divided into normal control group (n=10),normal+ EA group (n=10),surgical trauma (model) group (n=10),and model+EA group (n=10). Traumatic injury model was established by performing an exploratory laparotomy in the rats under anesthesia. EA (2 Hz/15 Hz,1-2 mA) was administered for 30 min via two stainless steel needles inserted in "Zusanli" (ST 36) and "Sanyinjiao" (SP 6). Serum adrenocorticotropic hormone (ACTH) ,corticosterone (Cort),luteinizing hormone (LH) and testosterone (T) contents were detected by double-antibody radioimmnoassay. Hypothalamic CRF and CRF R1 mRNA expression was assayed by reversed transcription polymerase chain reaction (RT-PCR) technique. Results The serum ACTH concentration decreased significantly in model group (P0.05). The serum Cort level increased significantly in model group(P0.05). The expression of hypothalamic CRF mRNA decreased significantly in model group (P0.05). Conclusion EA of "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) can improve surgical trauma-induced HPA disorders,which is probably related to its effects in upregulating CRF mRNA expression and downregulating Ucn 1 mRNA expression in the hypothalamus.