Vascular renin as a determinant of the circulatory response to renin

The effect of an injection of partially purified rat renin on the blood pressure, plasma and aortic renin was studied in rats 18 hours after bilateral nephrectomy. Blood pressure rose and remained elevated 6 hours after renin injection, returning to normal at 9 hours. Aortic renin concentration was increased and showed a similar response pattern to blood pressure whereas plasma renin concentration fell to subnormal levels within 3 hours. The blood pressure response was prevented by converting enzyme inhibition and at 3 and 6 hours was reversed by saralasin infusion. These results demonstrate that circulating renin is taken up by vascular tissue and the pressor response to exogenous renin is related to aortic but not plasma renin.