Culman J, Kopin I J, Saavedra J M
German Institute for High Blood Pressure Research, Heidelberg, Germany.
Endocr Regul. 1991 Sep;25(3):151-8.
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)
在大鼠中研究了垂体 - 肾上腺皮质系统对急性或反复制动（IMO）应激的激素反应。与急性应激的大鼠相比，反复应激的大鼠血浆促肾上腺皮质激素（ACTH）反应明显降低，但血浆皮质酮反应未见差异。急性而非反复的IMO导致垂体前叶ACTH含量显著降低，但在经受急性或反复应激的动物中，垂体中间 - 后叶或正中隆起（ME）中的ACTH含量未发现变化。急性IMO引起ME中促肾上腺皮质激素释放激素（CRF）含量显著降低。反复应激大鼠ME中CRF的基础浓度与完整对照组无差异；反复应激大鼠随后暴露于IMO导致ME中CRF含量无明显降低。对两组大鼠（对照组和反复应激组）外周注射CRF（每只大鼠50和500 ng）后，均观察到血浆ACTH呈剂量依赖性增加，然而，两组之间对CRF的ACTH反应未见差异。对照组和反复应激大鼠对外周给予高剂量CRF的血浆皮质酮反应无差异，而反复应激大鼠对低剂量CRF的血浆皮质酮反应大于对照组。（摘要截断于250字）
