VASOPRESSIN-CRF-ACTH INTERACTIONS

本研究将探讨神经垂体后叶加压素在中枢神经系统的作用。 促肾上腺皮质激素和皮质醇分泌的调控及其作用 促肾上腺皮质激素释放因子在加压素和促肾上腺皮质激素控制中的作用 清醒狗的分泌物。神经垂体切除术减轻ACTH 对低血压的反应和减弱对绵羊的皮质醇反应 促肾上腺皮质激素释放激素(CRF)诱导ACTH升高。促肾上腺皮质激素和皮质醇对 硝普钠引起的钳制降压和外源性降压 绵羊CRF的输注将在完好无损的狗身上确定， 持续使用加压素替代的神经垂体切除犬， 无后叶加压素替代的神经垂体切除犬(糖尿病 Insipidus)。这将确定衰减的ACTH反应是否 CRF诱导的低血压和皮质醇反应减弱 神经垂体切除犬促肾上腺皮质激素可恢复正常 缓解尿崩症的症状。急性输注阿司匹林 神经垂体切除犬低血压时加压素的升高作用 在完好无损的狗身上观察到的加压素水平将被用来确定 如果ACTH对低血压的全部反应需要血浆大幅增加 加压素。此外，外源性ACTH输注将用于 直接评估加压素在肾上腺皮质敏感性中的作用 (皮质醇、醛固酮和肾上腺雄激素)。 绵羊CRF静脉注射。清醒的狗会升高血浆中的加压素水平。 我们将向CRF注入和不注入高渗盐水，以确定是否 加压素对CRF的反应与渗透压受体的输入相互作用。在……里面 此外，地塞米松的阻断将被用来确定 加压素对CRF的反应，与ACTH一样，对糖皮质激素敏感 负面反馈。 自从CRF的测序和合成以来，对CRF相互作用的研究 CRF和加压素已经很多了。在此提出的研究将 检查神经垂体、加压素、促肾上腺皮质激素释放激素和类固醇的作用 反馈在控制垂体前、后叶功能中的作用 肾上腺皮质。

This study will investigate the role of neurohypophyseal vasopressin in the control of ACTH and cortisol secretion and the role of corticotropin-releasing factor (CRF) in the control of vasopressin and ACTH secretion in conscious dogs. Neurohypophysectomy attenuates the ACTH response to hypotension and attenuates the cortisol response to ovine CRF-induced increases in ACTH. The ACTH and cortisol response to nitroprusside-induced clamped decreases in blood pressure and to exogenous ovine CRF infusions will be determined in intact dogs, neurohypophysectomized dogs with continuous vasopressin replacement, and in neurohypophysectomized dogs without vasopressin replacement (diabetes insipidus). This will determine if attenuated ACTH responses to hypotension and attenuated cortisol responses to CRF-induced increases in ACTH in neurohypophysectomized dogs can be restored to normal by alleviating the symptoms of diabetes insipidus. Acute infusions of vasopressin during hypotension in neurohypophysectomized dogs to elevate vasopressin levels observed in intact dogs will be performed to determine if the full ACTH response to hypotension requires large increases in plasma vasopressin. In addition, exogenous ACTH infusions will be used to directly assess the role of vasopressin in adrenocortical sensitivity (cortisol, aldosterone, and adrenal androgen) in conscious dogs. Ovine CRF given i.v. to conscious dogs elevates plasma vasopressin levels. We will infuse CRF with and without hypertonic saline to determine if the vasopressin response to CRF interacts with osmoreceptor input. In addition, dexamethasone blockade will be used to determine if the vasopressin response to CRF, like ACTH, is sensitive to glucocorticoid negative feedback. Since the sequencing and synthesis of CRF, studies of the interaction of CRF and vasopressin have been many. The studies proposed herein will examine the role of the neurohypophysis, vasopressin, CRF, and steroid feedback in the control of the anterior and posterior pituitary and the adrenal cortex.