Effect of portacaval shunt on sulfur amino acid metabolism in rats.

Male rats were subjected to portacaval shunts (PCS). Postoperative growth curves were similar between PCS and sham-operated control animals, with complete recovery of preoperative body weight occurring within 7 days. PCS rats had 30% smaller livers and 39% larger spleens at autopsy. Total liver levels of reduced glutathione were decreased by 38% in PCS rats. Sulfur amino acid metabolism was studied 6 wk after PCS by injection of L-[methyl-14C]- or L-[1-14C]methionine with 14CO2 collection or by similarly administering L-[35S]methionine or L-[35S] cysteine and measuring 24-h urinary 35SO4, [35S]taurine, and total 35S. There were no significant differences in 14CO2 production over an 8-h period between PCS and sham rats. PCS rats excreted 31% more 35SO4 and 25% more total 35S when injected with 0.9 mmol of [35S]methionine and excreted 38% less [35S]taurine than controls when injected with [35S]-cysteine. These results indicate altered sulfur amino acid metabolism in PCS rats, an animal model of portal-systemic shunting.