Dobson H, Essawy S A, Alam M G
Department of Veterinary Clinical Science, University of Liverpool, Leahurst, Neston, South Wirral.
J Endocrinol. 1988 Aug;118(2):193-7. doi: 10.1677/joe.0.1180193.
Stress is known to result in lowered female reproductive efficiency. The objective of this study was to examine how increased pituitary-adrenal activity may influence gonadotrophin release in anoestrous ewes. Various doses (0.06-1.0 mg) of a synthetic adrenocorticotrophic hormone (ACTH(1-24)) preparation were injected into ewes 30 min or 3 h before an i.v. injection of 500 ng gonadotrophin-releasing hormone (GnRH). The LH response to GnRH given 30 min after ACTH(1-24) was similar to that after GnRH alone, whereas the response 3 h after ACTH(1-24) was significantly lower, irrespective of the dose of ACTH(1-24). At 30 min and 3 h after ACTH(1-24) the concentrations of cortisol exceeded 50 nmol/l compared with baseline values of less than 10 nmol/l. The effect of ACTH(1-24) on oestradiol-induced LH release was also examined. Those ewes receiving 0.8 mg ACTH(1-24) depot and 50 micrograms oestradiol benzoate simultaneously had a preovulatory-type increase in LH 14-20 h later, similar to when oestradiol benzoate was given alone. None of the ewes receiving an additional 0.8 mg ACTH(1-24) depot 10 h after oestradiol benzoate had increases in LH concentration. The cortisol concentrations in all ewes receiving either one or two injections of ACTH(1-24) were greater than 35 nmol/l at 10 h after the oestradiol injection. However, concentrations of progesterone increased from 0.9 +/- 0.3 (S.E.M.) nmol/l at the time of the second ACTH(1-24) injection to 2.1 +/- 0.3 nmol/l after 2 h.(ABSTRACT TRUNCATED AT 250 WORDS)
已知应激会导致雌性生殖效率降低。本研究的目的是研究垂体 - 肾上腺活动增加如何影响处于发情间期的母羊促性腺激素的释放。在静脉注射500 ng促性腺激素释放激素（GnRH）前30分钟或3小时，向母羊注射不同剂量（0.06 - 1.0 mg）的合成促肾上腺皮质激素（ACTH(1 - 24)）制剂。ACTH(1 - 24)注射后30分钟给予GnRH时，LH对GnRH的反应与单独给予GnRH后的反应相似，而ACTH(1 - 24)注射后3小时的反应则显著降低，与ACTH(1 - 24)的剂量无关。与基线值低于10 nmol/l相比，ACTH(1 - 24)注射后30分钟和3小时时皮质醇浓度超过50 nmol/l。还研究了ACTH(1 - 24)对雌二醇诱导的LH释放的影响。同时接受0.8 mg ACTH(1 - 24)长效制剂和50 μg苯甲酸雌二醇的母羊，在14 - 20小时后LH出现排卵前类型的增加，类似于单独给予苯甲酸雌二醇时的情况。在苯甲酸雌二醇注射10小时后额外接受0.8 mg ACTH(1 - 24)长效制剂的母羊，LH浓度均未增加。在雌二醇注射10小时后，所有接受一次或两次ACTH(1 - 24)注射的母羊皮质醇浓度均大于35 nmol/l。然而，孕酮浓度从第二次注射ACTH(1 - 24)时的0.9±0.3（标准误）nmol/l在2小时后增加到2.1±0.3 nmol/l。（摘要截断于250字）
