Time course of vasopressin and oxytocin secretion after stress in adrenalectomized rats
Time course of vasopressin and oxytocin secretion after stress in adrenalectomized rats
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DOI：
10.1055/s-2005-861159
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发表时间：
2005-02-01
影响因子：
2.2
通讯作者：
Castro, M
中科院分区：
文献类型：
--
作者：
Laguna-Abreu, MTC;Koenigkam-Santos, M;Castro, M
为探讨加压素（AVP）和催产素（OT）在肾上腺切除术（ADX）后下丘脑-垂体-肾上腺调节中的作用，本实验观察了基础状态和束缚应激后不同时间（3 h、1、3、7和14 d）假手术组和ADX组大鼠血浆皮质酮、ACTH、AVP和OT浓度以及室旁核（PVN）AVP和OT含量的变化。ADX组动物的皮质酮水平检测不到，而假手术组动物的皮质酮和促肾上腺皮质激素在手术后3小时显着增加，然后降低到基础对照水平。ADX大鼠表现出高的基础ACTH水平与三相反应没有变化后制动。三小时后，ADX组显示出比假手术组更高的OT水平。Sham组和ADX组制动应激后OT均增加。AVP血浆水平在两组的基础或应激研究中均未发生变化。在基础和应激条件下，ADX后1天和3天下丘脑AVP含量均下降。ADX组在第3、7和14天的血浆渗透压显著降低。总之，在去除糖皮质激素负反馈后，存在不同的垂体-肾上腺轴设定点。加压素能和催产素能神经元在ADX或制动应激后ACTH分泌中的作用似乎不同。大细胞AVP是不太可能有助于ACTH分泌响应ADX或制动应力。另一方面，OT是由固定应激引起的，可能有助于短期ADX期间的促肾上腺皮质激素分泌。
To characterize the participation of vasopressin (AVP) and oxytocin (OT) in hypothalamus-pituitary-adrenal regulation after adrenalectomy (ADX), we evaluated corticosterone, ACTH, AVP and OT plasma concentrations and AVP and OT content of the paraventricular nucleus (PVN) at different periods (3 h, 1, 3, 7 and 14 days) in sham or ADX rats under basal conditions and after immobilization stress. ADX animals showed undetectable corticosterone levels, while sham animals showed a marked increase in corticosterone and ACTH 3 h after surgery, then lowering to basal control levels. ADX rats showed high basal ACTH levels with a triphasic response without changes after immobilization. After three hours, the ADX group showed higher OT levels than the sham group. OT was increased after immobilization stress in sham and ADX groups. AVP plasma levels did not change throughout the basal or stress studies in either group. There was a decrease in hypothalamic AVP content 1 and 3 days after ADX under basal and stress conditions. Plasma osmolality showed a significant decrease in the ADX group at 3, 7, and 14 days. In conclusion, there are different pituitary-adrenal axis set points after removal of the glucocorticoid negative feedback. The role of vasopressinergic and oxytocinergic neurons in the ACTH secretion after ADX or immobilization stress appears to differ. Magnocellular AVP is unlikely to contribute to ACTH secretion in response to ADX or immobilization stress. On the other hand, OT is elicited by immobilization stress and might contribute to the ACTH secretion during short-term ADX.