Ageing alters intrahypothalamic release patterns of vasopressin and oxytocin in rats
Ageing alters intrahypothalamic release patterns of vasopressin and oxytocin in rats
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DOI：
10.1046/j.1460-9568.2000.00030.x
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发表时间：
2000-04-01
影响因子：
3.4
通讯作者：
Neumann, ID
中科院分区：
文献类型：
--
作者：
Keck, ME;Hatzinger, M;Neumann, ID
衰老过程已被证明对人类和啮齿动物的下丘脑-神经垂体系统（HNS）和下丘脑-垂体-肾上腺皮质（HPA）轴具有深远的影响。因此，在这项研究中，脑内和外周血管加压素和催产素的释放模式进行了研究，在老年雄性Wistar大鼠的基础条件下，并在行为学相关的压力，分别使用脑内微透析和慢性血液采样技术。大约两倍高的基础释放精氨酸加压素（AVP）下丘脑室旁核（PVN）内，但不是在视上核（SON），被发现在老年大鼠，而基础催产素（OXT）的释放与年轻大鼠相比没有差异。随着年龄的增长，增加在PVN内释放的AVP和OXT的钝化响应于强迫游泳。相反，SON内AVP的释放与年龄无关。同时记录的基础分泌AVP和OXT从神经垂体到血液中的老年大鼠增加，与钝OXT响应游泳应激。与此相反，血浆AVP水平在两组中保持不变。老年大鼠血浆促肾上腺皮质激素（ACTH）和皮质酮的基础水平升高，而应激引起的ACTH和皮质酮反应是不可区分的。这些结果表明，与年龄相关的变化，在HNS和HPA轴与增强的基础活动，而不是随着年龄的增加，对压力的迟钝反应。PVN内AVP基础释放的增加表明脑内AVP在HPA轴调节的年龄相关改变中的作用。
The ageing process has been shown to have a profound impact on the hypothalamo-neurohypophysial system (HNS) and the hypothalamo-pituitary-adrenocortical (HPA) axis in humans as well as in rodents. Therefore, in this study, the intracerebral and peripheral release patterns of both vasopressin and oxytocin have been studied in aged male Wistar rats under basal conditions and in response to ethologically relevant stressors, using intracerebral microdialysis and chronic blood sampling techniques, respectively. Approximately a twofold higher basal release of arginine vasopressin (AVP) within the hypothalamic paraventricular nucleus (PVN), but not within the supraoptic nucleus (SON), was found in aged rats, whereas basal oxytocin (OXT) release did not differ in comparison with young rats. With increasing age the rise in intra-PVN release of both AVP and OXT was blunted in response to forced swimming. In contrast, the intra-SON release of AVP was unrelated to age. Simultaneously recorded basal secretion of both AVP and OXT from the neurohypophysis into blood was increased in aged rats, with a blunted OXT response to swim stress. Opposed to that, plasma AVP levels remained unchanged in both groups. Basal plasma levels of corticotropin (ACTH) and corticosterone were elevated in aged rats, whereas stress-elicited ACTH and corticosterone responses were indistinguishable. These results indicate age-related changes in the HNS and HPA axis with an enhanced basal activity opposed to a blunted response to stressors with increasing age. The increased basal release of AVP within the PVN suggests a role of intracerebral AVP in age-associated alterations of HPA axis regulation.