Effects of morphine and naloxone on inhibition by ovarian hormones of pulsatile release of LH in ovariectomized rats.
Effects of morphine and naloxone on inhibition by ovarian hormones of pulsatile release of LH in ovariectomized rats.
复制标题
吗啡和纳洛酮对去卵巢大鼠卵巢激素脉冲性释放 LH 的抑制作用。
作者：
P. Sylvester;D. V. Van Vugt;C. Aylsworth;E. Hanson;J. Meites
本研究的目的是确定吗啡和纳洛酮对卵巢类固醇治疗（或未治疗）去卵巢大鼠黄体生成素脉冲释放的影响。去卵巢大鼠在实验前3天皮下注射苯甲酸雌二醇（20微克）或苯甲酸雌二醇（20微克）和黄体酮（10毫克）。各组大鼠每小时静脉注射纳洛酮（2 mg/kg）、吗啡（5 mg/kg）或0.87% NaCl，持续3 h。在给药15 min后，每15 min心房插管取血0.3 ml，持续3 h。苯甲酸雌二醇或与孕酮联用抑制脉动性LH释放。纳洛酮能够抵消这些类固醇对脉动性LH释放的抑制。提示内源性阿片肽参与了雌激素和黄体酮对脉动性LH释放的负反馈作用。吗啡对类固醇抑制搏动LH释放无影响。
The purpose of this study was to determine the effects of morphine and naloxone on pulsatile release of LH in ovariectomized rats treated (or untreated) with ovarian steroids. Ovariectomized rats were given a subcutaneous injection of estradiol benzoate (20 micrograms) or estradiol benzoate (20 micrograms) and progesterone (10 mg) 3 days prior to experimentation. The rats were then given intravenous injections of naloxone (2 mg/kg), morphine (5 mg/kg), or 0.87% NaCl every hour for 3 h. For LH assays, 0.3 ml blood was collected via an atrial cannula 15 min after drug treatment and every 15 min thereafter for 3 h. Pulsatile LH release was suppressed by estradiol benzoate or the combination of estradiol benzoate and progesterone. Naloxone was able to counteract inhibition of pulsatile LH release by these steroids. These results suggest that the endogenous opioid peptides are involved in the negative feedback exerted by estrogen and progesterone on pulsatile LH release. Morphine had no effect on steroid inhibition of pulsatile LH release.