The role of tubuloglomerular feedback in acute impairment of renal function in obstructive jaundice.

Acute renal functional impairment not infrequently accompanies liver dysfunction and, particularly with bile duct obstruction, may be extremely severe. Recent studies suggest that tubuloglomerular feedback (TGF) activated by circulating non-electrolyte factors which occur during liver dysfunction may contribute to the intense renal vasoconstriction thought to be central to the functional renal impairment. In this study, serum from two patients with obstructive jaundice (OJ) and renal impairment, and from rats with OJ due to bile duct ligation were either dialysed or treated with furosemide, known to block electrolyte-mediated TGF. These sera, when perfused into loops of Henle in rat nephrons, induced a significant fall of 28% in stop-flow pressure, an indirect measure of glomerular capillary pressure thus implying arteriolar vasoconstriction. These findings are consistent with the hypothesis that circulating, non-electrolyte factors, which stimulate TGF, occur in cases of obstructive jaundice and that these may contribute to the renal impairment.