Effect of renal nerve stimulation on urine and tissue kininogenase activity in cats.

SUMMARY The effect of electrical stimulation of efferent renal nerves on urine and renal tissue kininogenase activity was studied in cats. Handling renal nerves before crushing produced a significant increase in mean blood pressure (BP) in intact animals. After crushing, stimulation of efferent fibers (15 V, 0.5 msec, and 25 Hz) by 15-second train duration and at 2.45-minute intervals did not alter the average renal blood flow (RBF) or BP over 30 minutes. Glomenilar filtration rate, water, and potassium excretion rates did not change significantly in either kidney. Sodium excretion in the ipsilateral kidney decreased significantly (p < 0.05) in both intact and adrenalectomized cats. In intact animals, the kininogenase activity of urine (UK) also decreased significantly in both kidneys during nerve stimulation. In adrenalectomized animals it decreased significantly (p < 0.05) only in the ipsilateral kidney, and UK of the ipsilateral kidney was significantly lower than in the contralateral (p < 0.05). In both groups of cats, UK returned to control values during the recovery period of 30 minutes after stimulation. Adrenergic blockade abolished the effect of nerves stimulation on sodium and UK. Renal tissue kininogenase activity (RK) per gram of wet tissue was significantly lower in adrenergically blocked animals. No differences were detected when comparing RK content of ipsilateral vs contralateral kidney. These results suggest that renal nerve stimulation may produce a decrease in UK through a release of adrenal and peripheral nerve ending catecholamines. (Hypertension 3 (suppl II): II-50-II-54, 1981)