Complete occlusion of a renal artery branch on glomerular and tubular function

¹ Department of Physiology, University of Oregon Medical School, Portland, Oregon

Experiments were made on anesthetized, laparotomized dogs to define alterations in glomerular and tubular function occurring when a branch of the left renal artery is occluded. Diuresis was induced by intravenous infusion of glucose, NaCl or urea solutions. Branch-artery occlusion on the left induced variable increases in filtration rate/tubule on the left only and increased fraction of filtered water excreted (V/C_cr) from both kidneys except when the left kidney was denervated during operative preparation. V/C_cr increased whether or not filtration/tubule increased. Branch-artery occlusion distorted the usual relationship between urine solute concentration and urine flow but not between urine solute concentration and V/C_cr, indicating that increased urine flow/tubule was osmotically induced and not a water diuresis. Thus, reduction of functional renal mass from branch-artery occlusion, frequently and inexplicably increased filtration/tubule in the ipsilateral kidney and independently initiated bilateral decrease in solute and water reabsorption that may have been mediated via the sympathetic nervous system.