Acute Effects of Denervation on Kidney Function in the Dog

Alterations in renal function produced by acute renal denervation were studied in anesthetized and unanesthetized female dogs and in crossed perfusion preparations. Initially, the renal nerves of both kidneys were isolated under anesthesia, and silk thread placed loosely around the nerve bundles and brought to the outside through a flank incision. Ureteral catheters were inserted and tied in place. Urine was collected on succeeding days and after a suitable control period one kidney was acutely denervated by a single pull on the thread, following which urine samples were collected. In the crossed perfusion preparation the left kidney received its entire blood supply from the carotids of a donor dog. The nerves were intact during control periods. Glomerular filtration rate, renal plasma flow, water excretion and sodium and potassium excretory rates were studied before and after denervation. Renal arterial pressure was rigidly controlled and experimentally altered throughout. Results indicate that acute denervation produces a significant and immediate increase in urinary sodium concentration and excretion and that this increase is independent of any alteration in renal hemodynamics. A direct influence of the renal nerves on reabsorbtive activity of renal tubules is suggested.