VASOPRESSIN-CRF-ACTH INTERACTIONS

本研究将探讨神经垂体加压素在脑缺血再灌注中的作用。 ACTH和皮质醇分泌的控制以及 促肾上腺皮质激素释放因子（CRF）对血管加压素和ACTH的调节作用 有意识的狗的分泌物。 神经垂体切除术减弱ACTH 对低血压的反应和减弱皮质醇对绵羊的反应 CRF诱导的ACTH增加。 促肾上腺皮质激素和皮质醇对 硝普钠诱导的钳夹性血压下降和外源性 绵羊CRF输注将在完整的狗中测定， 神经垂体切除的狗，持续加压素替代， 没有加压素替代的神经垂体切除的狗（糖尿病 尿崩症）。 这将决定是否减弱ACTH反应， 低血压和减弱皮质醇反应CRF诱导的增加， ACTH在神经垂体切除的狗可以恢复正常， 减轻尿崩症的症状。 急性输注 垂体后叶素在神经垂体切除犬低血压期间升高 将在完整犬中观察血管加压素水平，以确定 如果对低血压的全部ACTH反应需要大量增加血浆 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）在清醒的狗。 对清醒犬静脉注射绵羊CRF可升高血浆加压素水平。 我们将在CRF中输注高渗盐水和不输注高渗盐水，以确定 加压素对CRF的反应与β受体输入相互作用。 在 此外，地塞米松阻滞将用于确定是否 加压素对CRF的反应与ACTH一样，对糖皮质激素敏感 负反馈 自从CRF的排序和合成以来， CRF和加压素的作用也很多。 本报告提出的研究将 检查神经垂体、加压素、CRF和类固醇的作用 反馈控制的前，后垂体和 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.