Regulation of corticotropin-releasing hormone and pituitary-adrenocortical response during acute and repeated stress in the rat.
Regulation of corticotropin-releasing hormone and pituitary-adrenocortical response during acute and repeated stress in the rat.
复制标题
大鼠急性和反复应激期间促肾上腺皮质激素释放激素和垂体肾上腺皮质反应的调节。
作者：
J. Culman;I. Kopin;Saavedra Jm
本文研究了大鼠垂体-肾上腺皮质系统对急性或反复制动（IMO）应激的激素反应。与急性应激大鼠相比，反复应激大鼠血浆ACTH反应明显降低，但血浆皮质酮反应无差异。急性但不重复的IMO引起垂体前叶ACTH含量的显着减少，但没有发现在垂体中后叶或正中隆起（ME）的ACTH含量的变化在动物暴露于急性或重复的压力。急性IMO可引起ME中促肾上腺皮质激素释放激素（CRF）含量显著降低，而反复应激大鼠ME中CRF的基础浓度与正常对照组无明显差异;反复应激大鼠随后暴露于IMO导致ME中CRF含量的显著降低。（50和500 ng/只）在对照和反复应激大鼠中均观察到血浆ACTH的剂量依赖性增加，然而，在这两组之间未观察到ACTH对CRF的反应的差异。血浆皮质酮的反应，高剂量的外周给药CRF之间没有显着差异，控制和反复强调的大鼠，而血浆皮质酮的反应，低剂量的CRF是在反复强调的大鼠比对照组。（250字处删节）
The hormonal response of the pituitary-adrenocortical system to acute or repeated immobilization (IMO) stress was studied in rats. Plasma ACTH response was markedly reduced in repeatedly stressed rats compared to acutely stressed ones, but no differences in plasma corticosterone responses were seen. Acute but not repeated IMO caused a marked reduction of the ACTH content in the anterior pituitary, but no changes of the ACTH content were found in the intermediate-posterior pituitary or in the median eminence (ME) in animals exposed to either acute or repeated stress. Acute IMO elicited a marked reduction of the content of corticotropin releasing hormone (CRF) in the ME. The basal concentration of CRF in the ME of repeatedly stressed rats did not differ from that in intact controls; subsequent exposure of repeatedly stressed rats to IMO caused an insignificant reduction of the CRF content in the ME. In response to peripheral injections of CRF (50 and 500 ng per rat) a dose dependent increase of plasma ACTH was observed in both control and repeatedly stressed rats, however, no differences in ACTH responses to CRF were seen between these two groups. Plasma corticosterone response to the high dose of peripherally administered CRF did not differ between control and repeatedly stressed rats, while plasma corticosterone response to the low dose of CRF was greater in repeatedly stressed rats than in controls.(ABSTRACT TRUNCATED AT 250 WORDS)