CARDIOVASCULAR EFFECTS OF ATRIOPEPTIN III

心脏的心房合成一个家族 利尿/利钠/血管扩张肽称为心房肽。 目的 这项研究的目的是研究血液动力学的变化， 静脉注射外源性合成心房肽III。 我们的目标是了解更多 关于心房肽素III在各种条件下的生理学， 确定这种激素何时可能在调节血液中起重要作用 血压和心输出量 将通过以下方法监测血流变化： 同时在肾脏， 肠系膜和后躯（肌肉）阻力床。 血压和 心率也将同时监测， 肾、肠系膜和后肢血管床的阻力将 在每个心动周期期间计算的响应持续时间 心房肽素III。 在其他大鼠中，脉冲多普勒血流探头将 放置在升主动脉上，以测量总心输出量的变化 和总外周阻力。 实验旨在比较 在水剥夺状态与正常状态下对心房肽III的反应 水化与容量负荷以及在钠剥夺条件下与 正常钠摄入量vs高钠摄入量， 长期输注醛固酮、抗利尿激素或 促肾上腺皮质激素 还将测定心房肽素III的血浆水平。 在这些生理条件中的每一种下测定， 给予外源性心房肽III。 重要的是要了解 更多关于心房肽系统的心血管生理学， 最终研究其在某些疾病的病理生理学中的可能作用， 钠敏感型或容量敏感型充血性高血压 心力衰竭、肾功能不全和内分泌失调。

The atria of the heart synthesize a family of diuretic/natriuretic/vasodilator peptides called atriopeptins. The purpose of this investigation is to study hemodynamic changes in response to intravenous exogenous synthetic atriopeptin III. The goal is to learn more about the physiology of atriopeptin III under various conditions to determine when this hormone may be important in the regulation of blood pressure and cardiac output. Blood flow changes will be monitored by means of directional pulsed-Doppler flowmetric technique simultaneously in renal, mesenteric and hindquarter (muscle) resistance beds. Blood pressure and heart rate will also be monitored simultaneously and regional changes in resistance in the renal, mesenteric and hindquarter vascular beds will be calculated during each cardiac cycle for the duration of the response to atriopeptin III. In other rats, the pulsed-Doppler flowprobe will be placed on the ascending aorta to measure changes in total cardiac output and total peripheral resistance. Experiments are designed to compare the responses to atriopeptin III in states of water deprivation vs normal hydration vs volume load and under conditions of sodium deprivation vs normal sodium intake vs high sodium intake and in animals that are being infused chronically with aldosterone, with antidiuretic hormone, or with adrenocorticotropin. Plasma levels of atriopeptin III will also be determined under each of these physiological conditions before the administration of exogenous atriopeptin III. It is important to understand more about the cardiovascular physiology of the atriopeptin system in order to eventually study its possible role in the pathophysiology of certain sodium-sensitive or volume-sensitive forms of hypertension, congestive heart failure, renal insufficiency and endocrine disorders.