Abstract
Renal blood flow and filtration rate was studied in 35 subjects with and without arterial hypertension during periods of elevation of blood pressure induced by discussion of important personal topics having a threatening significance. During these rises in blood pressure, there was a fall in effective renal blood flow and rise in filtration fraction and vascular resistance, of both the afferent and efferent glomerular arteriole. These changes were similar in direction in both the normotensive and hypertensive groups but were quantitatively greater in the latter. Identical studies done before and after lumbodorsal sympathectomy and splanchnicectomy, indicated a complete or partial reversal of the above pattern, there being a fall in filtration fraction and less intense total renal vasoconstriction. Analysis of the data by the formulae of Lamport (Jour. Clin. Invest. 20: 535, 545. 1941; 21: 685. 1942; 22: 461. 1943) and Gomez (Rev. Scientifique, 1947: 451; and Federation Proc. 7: 41. 1948), suggested a failure of the efferent glomerular arteriole to participate in the renal vascular response to stress after operation. The concept is advanced that the kidney, under usual conditions, has 2 more or less independent vascular mechanisms within it: a sympathetic control of the efferent glomerular arteriole, and an intrinsic intrarenal humoral control of the afferent glomerular arteriole, possibly involving the juxtaglomerular myoarterial apparatus.