EXPERIMENTAL STUDIES IN RENAL BLOOD FLOW

REPORT 1ST: INFLUENCE OF AORTIC BLOOD PRESSURE UPON RENAL BLOOD FLOW IN THE DOG KIDNEY

Abstract

Influence of aortic blood pressure upon renal blood flow was investigated, recording continuously the pressure by an electric manometer and the renal blood flow in the dog kidney by an electromagnetic flow-meter respectively at the same time. Thirty and five mongrel dogs of healthy adult were used, and anesthetized by intravenous injection of 0.3per cent solution of Isozol (sodium 5-allyl-5 (1-methyl)-2-thiobarbiturate), and by endotracheal tube inhalation of ether and oxygen. The results obtained are as follows.
1) By depleting blood, the renal blood flow was obviously decreased in parallel with levels of the pressure which fell down within normal range. However, by transfusion of the blood depleted in the previous experiment, the renal blood flow was not increased rapidly as to arrive at the control amount of the renal blood flow. On the other hand, the pressure was arrived rapidly at the control levels of the pressure by the transfusion.
2) By an intravenous injection of Methobromin, the renal blood flow was decreased gradually in parallel with fall of the pressure, however the decrease in the renal blood flow was not so much as in the blood-letting.
3) Following intravenous infusion of rapid large amount of Ringer's solution, physiologic saline solution and 5per cent dextrose solution, the renal blood flow increased gradually in parallel with a rise in the pressure, except that no increase in the renal blood flow was observed when no any change of the pressure was found practically.
Following the infusion of 20 and 50per cent solution of dextrose separately, an increase in the renal blood flow was obviously observed, and a maximum of the increase was indicated at 8 minutes after the beginning of the infusion, although a rise in the pressure was observed insignificant, and the maximum from 1.5 to 2.0 times of the control amount of the renal blood flow. A rate of the increase after the infusion of 50per cent dextrose solution was larger than of 20per cent dextrose solution, however the rate was not above 2.5 times of the increase of the 20per cent dextrose solution.
A change in blood flow of Vena iliaca externa was observed approximately as much as one of the renal blood flow, following the infusion of these solution.
4) By an intravenous injection of Adrenalin, a rapid sharp increase in the pressure and a remarkable decrease in the renal blood flow were observed. However, any change in the pressure and in the renal blood flow was not found, following the injection of Adrenalin into Recipient on experiment of Parabiose.
A blood flow in the Vena iliaca externa was slightly decreased at first and clearly increased later, by the injection of Adrenalin.
5) By the intravenous injection of Hydergine, the renal blood flow was decreased in parallel with fall in the pressure. On the contrary, the blood flow in Vena iliaca externa was increased a little.
By the intravenous injection of Atropine sulfate, the pressure was not changed while the renal blood flow was rapidly decreased, and the decrease was about 70 per cent. Following the injection of Atropine sulfate at five minutes and 40 seconds after of Hydergine, a rise in pressure and a decrease in the renal blood flow were observed conspicuously.
6) It was observed that the pressure was slightly fallen and the renal blood flow was decreased 40 per cent of the control amount of the renal blood flow by the intravenous injection of Imidalin.
Furthermore, a rise in the pressure and a considerable decrease in the renal blood flow were observed by the injection of Adrenalin at 2 minutes after of Imidalin.
By the intravenous injeceion of Pilocarpine hydrochloride at 2 minutes after of Imidalin, the pressure was decreased, and the renal blood flow was increased just a little at first, however, decreased at 50 per cent of the control amount of the renal blood flow later.
7) By the intravenous injection of 0.3per cent solution of Isozol into Recipient on