Hamlyn J M, Levinson P D, Ringel R, Levin P A, Hamilton B P, Blaustein M P, Kowarski A A
Fed Proc. 1985 Sep;44(12):2782-8.
Elements of a hypothesis that relate endogenous digitalis-like factors to both natriuretic hormone and hypertension are briefly reviewed. The stimulus for secretion of these factors appears to involve a tendency toward a state of extracellular fluid volume expansion as a consequence of an inherited or an acquired defect in renal function. Several studies implicate the brain and, in particular, the hypothalamus in the control of the secretion. The digitalis-like factors are thought to act by partial inhibition of active sodium transport, thereby promoting increased intracellular levels of Na+ and Ca2+ in a variety of cell types. In the kidney, inhibition of sodium transport leads to a compensatory natriuresis to correct the tendency for volume overload. In smooth muscle, the inhibition of sodium transport will indirectly increase intracellular calcium levels. The increased availability of Ca2+ will elevate muscle tone and increase peripheral vascular resistance. Also presented are criteria that may be used to characterize digitalis-like activity in samples and extracts obtained from purification procedures. Finally, we review our measurements of the 6-h integrated plasma levels of digitalis-like factors and other hormones for normotensive subjects and patients with essential hypertension. The data indicate the presence of two classes of digitalis-like factors with potentially different roles in electrolyte metabolism and hypertension.
本文简要回顾了将内源性类洋地黄因子与利钠激素和高血压相关联的假说要素。这些因子的分泌刺激似乎涉及由于遗传性或获得性肾功能缺陷导致的细胞外液容量扩张状态的倾向。多项研究表明，大脑尤其是下丘脑参与了分泌的控制。类洋地黄因子被认为通过部分抑制主动钠转运起作用，从而促进多种细胞类型中细胞内Na+和Ca2+水平的升高。在肾脏中，钠转运的抑制导致代偿性利钠作用，以纠正容量超负荷的倾向。在平滑肌中，钠转运的抑制将间接增加细胞内钙水平。Ca2+可用性的增加将提高肌张力并增加外周血管阻力。还介绍了可用于表征从纯化程序获得的样品和提取物中类洋地黄活性的标准。最后，我们回顾了对正常血压受试者和原发性高血压患者的类洋地黄因子和其他激素的6小时综合血浆水平的测量。数据表明存在两类类洋地黄因子，它们在电解质代谢和高血压中可能具有不同的作用。
