The Hypertension-Reducing Function of the Kidney
THE recent synthesis of angiotonin (hypertensin) II by members of this Division1 has opened important vistas in the search for participation of humoral agents in the genesis of hypertension.
Angiotonin when injected into an experimental animal or a human being causes a rise in blood pressure. Does it follow that its pressor activity is responsible for human hypertensive cardiovascular disease or even for chronic experimental renal hypertension? Enough data to answer this question are not yet available.
In our enthusiastic recognition of the pressor substances, we should not forget that although the participation of the renin-angiotonin system in experimental renal hypertension seems beyond doubt, many phenomena can be better explained if it is assumed that the kidney in addition to its excretory function has two opposing blood-pressure-regulating functions. One of these is the liberation of renin. Renin acts on renin-substrate to form angiotonin. The second is the formation of a material that reduces elevated blood pressure.
I shall present a working hypothesis developed by Dr. Irvine H. Page and myself for the pathogenesis of hypertensive cardiovascular disease, which takes into account the experimental evidence obtained in animals deprived of their kidneys. The hypertension that then occurs is called “renoprival” hypertension. This review is not complete. I shall mention the facts that support our views and leave it to others to contradict them. I shall quote mainly from our own published work. Due credit to earlier investigators has been given in those earlier publications; here the concern is not with priority . . .