IN-VITRO AMMONIA UTILIZATION AND UREA SYNTHESIS BY RAT-LIVER AFTER PORTACAVAL-SHUNT

Background: Tile objective of this study was to study in vitro ammonia utilization and urea synthesis by the rat liver after portacaval shun t (PCS) in comparison to controls. This study is part of a series of e xperiments to investigate metabolic derangements in the liver followin g PCS. Methods: Sixteen male Wistar rats weighing 150-230 g were used. PCS was performed on 8 and the rest served as sham-operated controls. The experiments were performed 4 weeks postoperatively, The usually m onitored postoperative parameters after PCS like body weight, rise in ammonia levels in the peripheral blood, atrophy of mesenteric fat, atr ophy of the liver, etc., were comparable to other PCS series, Liver sl ices (1 x 2 x 1 mm) were prepared from each rat liver and incubated in Krebs-Henseleit buffer. Results: After incubation, ammonia utilizatio n in the controls was 162.88 +/- 20.12 mu mol/g dry weight/h while in PCS rats it was 81.35 +/- 2.64 mu mol/g dry weight/h (p < 0.0001), The rate of urea synthesis in controls was 122.54 +/- 12.93 mu mol/g dry weight/h whereas in the PCS group it was 14.99 +/- 2.21 mu mol/g dry w eight/h (p < 0.0001). Conclusion: These results indicate a significant decline in the capacity of the liver for ammonia utilization as well as urea synthesis after PCS.