1. We have studied kidney structure and function in female Sprague—Dawley rats with chronic obstructive jaundice after bile-duct ligation and section and in age-matched sham-operated control animals.
2. High bile-duct ligation and section resulted in immediate hyperbilirubinaemia and progressive hepatomegaly with histological evidence of bile-duct proliferation and periportal inflammation and fibrosis.
3. Only 20% of the jaundiced animals developed ascites, but 42% became hypotensive and died during preparation for micropuncture.
4. In the surviving rats there was no significant change in blood pressure, whole-kidney glomerular filtration rate, single-nephron glomerular filtration rate or calculated glomerular capillary hydrostatic pressure from control animals. However, renal plasma flow was increased so that whole-kidney filtration fraction was low. These changes were largely reversed by choledochoduodenostomy.
5. Proximal tubular reabsorption in the jaundiced group was not different from control rats, although the inulin (urine/plasma) ratio was significantly reduced, indicating diminished reabsorption distal to the proximal convoluted tubule. Proximal intratubular hydrostatic pressure was significantly increased in some nephrons.
6. Electron microscopy of the glomeruli from the jaundiced animals revealed evidence of marked increase in activity of both epithelial and endothelial cells.
7. Rats who survive chronic obstructive jaundice for 3–4 weeks have changes in renal function and also structural changes suggestive of diminished glomerular permeability.