Renal function in chronic obstructive jaundice: a micropuncture study in rats.

1. We have studied kidney structure and func­ tion 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 bileduct proliferation and periportal inflammation and flbrosis. 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 jaun­ diced group was not different from control rats, although the inulin (urine/plasma) ratio was sig­ nificantly reduced, indicating diminished reab­ sorption distal to the proximal convoluted tubule. Proximal intratubular hydrostatic pressure was sig­ nificantly increased in some nephrons. 6. Electron microscopy of the glomeruli from the jaundiced animals revealed evidence of marked