Renal hemodynamic response to l-dopa during acute renal failure in man

Twelve patients with acute renal failure underwent L.dopa infusion into a renal artery and 133Xenon wash-out recordings before and during the infusion. Urine volume and sodium output were also compared during two 24 hours periods, before and after the procedure. Hemodynamic data were compared with data obtained from a matched group of patients receiving Furosemide (8 patients) in place of L.dopa. Only L.dopa infusion significantly increased outer cortical distribution (p less than 0.005 using paired t-test). No blood flow change could be demonstrated in any component nor did the drug improve urinary excretion or the general course of the disease. Control data shows that reduced cortical distribution is the most consistent feature of acute renal failure, so that L.dopa does partially improve intrarenal hemodynamics in this condition. The failure of the drug to restore kidney function may be explained by the following reasons: a) Inability of the agent to restore a normal wash-out pattern; b) Involvement of non-hemodynamic factors, as suggested by comparing similar wash-out improvements after L.dopa in acute glomerulonephritis and in reversible acute renal failure.