高血圧症と腎機能(第2報) : 第三部 実験的高血圧症

A variety attempts have been made over many years to produce persistent hypertension by surgical procedures on the kidney. But one of the difficulties to decide the exact role of the kidney in hypertension was that the hypertension should be produced without disturbances of renal excretory functions. Goldblatt and Page overcame this disadvantage by the application of constricting clamps on the renal arteries or by cellophane perinephritis.Here, I studied the renal hemodynamics in renal experimental hypertensions-Goldblatt's hypertension, Page's hypertension and nephrectomy. And then I attempted to evaluate the relationship between blood pressure and renal blood flow.In Goldblatt's experiment, 14 trained dogs were used. Renal plasma flow was determined by paraaminohippurate clearance method at low plasma level, glomerular filtration rate measured by sodium thiosulfate clearance method, and TmG was measured, too. These renal function studies were carried out every 1-2 weeks during the experimental period. Blood pressure was measured directly on the femoral artery with a needle connected to a mercury manometer.Among 14 Goldblatt's dogs, 2 were slightly, 1 moderately and 4 markedly hypertensive. Percentage of success was 50% It the cases with transient elevation of blood pressure were included in the group of success, it was 85.7%.Considering the experiment of Goldblatt's procedure, it seems as follows : 1) There exists relationship between RBF and elevation of blood pressure, 2) renal ischemia causes an elevation of blood pressure, and the elevated blood pressure saves ischemia, but on the other hand, it improves damages of the kidneys ; so there appears an improvement of the renal ischemia. In Goldblatt's hypertensin, a "dynamic equilibrium" is, therefore, observed between renal ischemia and blood pressure elevation, and 3) this "dynamic equilibrium" is probably produced by a humoral substance of renal origin which may be Maekawa's "Kidney-ATPase".In Page's procedure, 8 dogs were used. Among these subjects, 1 slightly, 1 moderately and 2 markedly hypertensive following Page's procedure. Percentage of success was 50%. If the cases with transient elevation of blood pressure were included in successful, percentage of success was 62.2%. But in cellophane perinephritis, RPF was decreased progressively and the blood pressure elevated more and more. Therefore, a "dynamic equilibrium" was not obtained between blood pressure and RPF. This point is the difference between Goldblatt's and Page's hypertension.By unilateral nephrectomy, a significant elevation of blood pressure did not occur.In conclusion, although there is parallelism between elevated blood pressure and decrease of renal plasma flow, it is not always the case in chronic stage. However, it is sure that a gradual decrease, especially a progressive decrease of RPF relates to the elevation of blood pressure.It follows therefore that : 1) The necessary condition of the kidney for the elevation of blood pressure is the "dynamic equilibrium" between ischemia and blood pressure elevation, which is related to the condition of kidney. It follows that the kidney is related to the pathogenesis of hypertension as merely one special condition.2) This special condition causes a disturbance of the ATP-ATPase system of kidney, and makes the release of ATPase of kidney into the blood stream possible.