REGULATION OF ANF RELEASE FROM A HEART-LUNG PREPARATION

最近的研究表明，心钠素(ANF)是一种 循环激素，可能参与调节血容量和 动脉压，但对生理性血压了解甚少 心钠素分泌的调节。一个已被证明可以释放的因素 ANF是指心房伸展或容量的增加。重要的是要 确定哪些其他因素会影响ANF的分泌，以及这些因素 这些因素直接影响ANF的释放或通过调节ANF起作用 对心房扩张的反应。为此，一只大鼠心肺 已经开发出一种既有静脉回流又有主动脉回流的制剂 压力可以调节，ANF可以直接从灌流中测量 用放射免疫测定法测定储集层。这个项目的具体目标是：1) 确定灌流液钠浓度的增加是否有直接的 对ANF释放的影响，2)确定血管紧张素II或ADH是否有 直接负反馈对心钠素分泌的影响，3)检验其影响 静脉回流时心钠素释放时心脏后负荷增加 常数，4)以确定α或β肾上腺素能的直接影响 主动脉压升高时受体对心钠素释放的刺激 和静脉回流保持不变，5)以检验以下假设 多巴胺在心钠素的分泌中起作用。假设ANF扮演的是 在控制血浆钠浓度和血管紧张素中的作用 II和ADH，在血容量减少的情况下释放， 会对ANF的分泌产生抑制作用。心脏疾病的增加 后负荷应通过增加心房压力来增加心钠素的释放。 尽管一些研究表明，肾上腺素能刺激会增加ANF 在体内释放，有可能是β或α肾上腺素能刺激 对ANF的分泌有直接的抑制作用。由于多巴胺 拮抗剂可减轻小鼠的利钠和低醛固酮血症。 体积膨胀，预测多巴胺在ANF释放中起作用 发自内心的。这些研究将对我们理解 ANF在体液平衡中的生理作用。

Recent studies suggest that the atrial natriuretic factor (ANF) is a circulating hormone that may be involved in the regulation blood volume and arterial pressure but little is known concerning the physiological regulation of ANF secretion. One factor which has been shown to release ANF is an increase in atrial stretch or volume. It is important to determine what other factors influence ANF secretion and whether these factors have a direct effect on ANF release or act by modulating the ANF response to atrial distension. For this purpose, a rat heart-lung preparation has been developed in which both venous return and aortic pressure can be regulated and ANF measured directly from the perfusion reservoir by radioimmunoassay. The specific aims of this project are 1) to determine if increases in perfusate sodium concentration have a direct effect on ANF release, 2) to determine if angiotensin II or ADH have a direct negative feedback effect on ANF secretion, 3) to examine the effect of an increase in cardiac afterload on ANF release with venous return held constant, 4) to determine the direct effect of alpha or beta adrenergic receptor stimulation on ANF release under conditions where aortic pressure and venous return are held constant and 5) to test the hypothesis that dopamine plays a role in ANF secretion. It is hypothesized that ANF plays a role in the control of plasma sodium concentration and that angiotensin II and ADH, which are released under conditions of reduced blood volume, will have an inhibitory effect on ANF secretion. Increases in cardiac afterload should increase ANF release by increasing atrial pressure. Although some work suggests that adrenergic stimulation increases ANF release in vivo, it is possible that beta or alpha adrenergic stimulation has a direct inhibitory effect on ANF secretion. Since dopamine antagonists attenuate the natriuresis and hypoaldosteronism produced by volume expansion, it is predicted that dopamine plays a role in ANF release from the heart. These studies will be important in our understanding of the physiological role of ANF in body fluid balance.