Jezova D, Skultetyova I, Tokarev D I, Bakos P, Vigas M
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia.
Ann N Y Acad Sci. 1995 Dec 29;771:192-203. doi: 10.1111/j.1749-6632.1995.tb44681.x.
Though oxytocin and vasopressin are similar in structure and are produced in the same brain regions, they show specific responses under stress conditions. In humans, increases in peripheral blood vasopressin appear to be a consistent finding during many acute stress situations, while in rats, vasopressin secretion is unresponsive to several stimuli known to induce ACTH and catecholamine release. Even decreases in vasopressin levels during stress were described. In accordance with others, we observed enhanced vasopressin release in response to stress stimuli with an osmotic component such as hypertonic saline injection but also during exposure of rats to a warm environment. Immobilization stress which fails to induce vasopressin release was reported to increase hypothalamic vasopressin mRNA and plasma vasopressin levels in chronically adreno-demedullated rats. Unlike vasopressin, oxytocin may be considered a typical stress hormone responding to osmotic as well as other stress stimuli. We found that acute exposure of rats to immobilization stress resulted in an increase in oxytocin mRNA level. In addition, we have shown that magnocellular neurons of the paraventricular nucleus, but not the supraoptic nucleus, are essential for oxytocin release during immobilization stress. The release of posterior pituitary hormones represents an important component of the stress response.
尽管催产素和血管加压素结构相似且在大脑相同区域产生，但它们在应激条件下表现出特定反应。在人类中，许多急性应激情况下外周血血管加压素水平升高似乎是一个一致的发现，而在大鼠中，血管加压素分泌对几种已知能诱导促肾上腺皮质激素和儿茶酚胺释放的刺激无反应。甚至有报道称应激期间血管加压素水平会降低。与其他人的研究结果一致，我们观察到，在受到具有渗透成分的应激刺激（如注射高渗盐水）时，以及在大鼠暴露于温暖环境期间，血管加压素释放会增强。据报道，在慢性肾上腺髓质切除的大鼠中，未能诱导血管加压素释放的固定应激会增加下丘脑血管加压素信使核糖核酸水平和血浆血管加压素水平。与血管加压素不同，催产素可被视为一种典型的应激激素，对渗透及其他应激刺激均有反应。我们发现，大鼠急性暴露于固定应激会导致催产素信使核糖核酸水平升高。此外，我们还表明，室旁核的大细胞神经元而非视上核的大细胞神经元，对于固定应激期间催产素的释放至关重要。垂体后叶激素的释放是应激反应的一个重要组成部分。
