The activities of rat hepatic cysteine dioxygenase and cysteinesulfinate decarboxylase are regulated in a reciprocal manner in response to dietary casein level.

摘要: The catabolism of cysteine and cysteinesulfinate, the activities key enzymes in catabolic pathways, effects inhibitors specific on were investigated hepatocytes isolated from rats fed low (100 g casein/kg diet), moderate (300 diet) or high (600 levels dietary protein. Cysteine was catabolized predominantly by cysteinesulfinate-dependent pathways. dioxygenase activity increased with increases casein level, higher enzyme paralleled a greater total catabolite production (taurine + hypotaurine sulfate) cysteine. However, taurine did not closely follow activity. Taurine doubled an increase 100 to 300 g/kg but further 600 g/kg. as percentage decreased progressively observed decreases cysteinesulfinate decarboxylase Thus, limited at protein decrease such that sulfate favored. D-Cysteinesulfinate inhibited cysteine, inhibition specific.