The in Vivo Effect of Angiotensin and Noradrenaline on the Proximal Tubular Reabsorption of Salt in Mammalian Kidneys

Leyssac, P. P. The in vivo effect of angiotensin and noradrenaline on the proximal tubular reabsorption of salt in mammalian kidneys . Acta physiol. scand. 1965. 64 . 167–175. – The purpose of the investigation presented here was to study the immediate effect of angiotensin and of noradrenaline on the rate of proximal tubular reabsorption of filtrate in mammalian kidneys by a direct method. By registration of the occlusion time, which is the time interval between interruption of the renal circulation and the moment at which the majority of the proximal tubules have completed reabsorption of the luminal fluid, it is demonstrated that angiotensin causes a depression of the tubular reabsorption rate, which is maximal when about 0.7 × 10 ‐9 g is acting per g of kidney. In contrast noradrenaline was without any immediate effect on the proximal reabsorption rate, suggesting that effects observed in clearance studies are indirect and mediated by a rapid intrarenal mechanism possibly involving the angiotensin system.