Rat liver cysteine dioxygenase

Table 1. Summary of purification of rat liver cysteine dioxygenase...

Table 3. Effects of hydrocortisone, L-cysteine, L-methionine on the rat liver cysteine dioxygenase activity...

Decrease of rat liver cysteine dioxygenase(cysteine oxidase) activity mediated by glucagon, J. Biochem. 84 419-424 (1978)... 

Sakakibara, S., Yamaguchi, K., Hosokawa, Y., Kohashi, N., Ueda, I., and Sakamoto, Y., 1976, Purification and some properties of rat liver cysteine oxidase (cysteine dioxygenase), Biochim. biophys. Acta (Amst.), 422 273. 

CYSTEINE DIOXYGENASE OF RAT LIVER SOME PROPERTIES AND ITS SIGNIFICANCE ON CYSTEINE IffiTABOLISM OF RAT... 

Cysteine dioxygenase was purified from rat liver cytoplasm to homogeneity. A summary of the purification procedure is given in Table 1. 

Induction of cysteine dioxygenase in rat liver by methionine and cysteine... 

We have found that cysteine oxidase activity in rat liver, which was assayed by NAD-depending assay system , was induced by either cysteine or methionine in the presence of permissive amounts of glucocorticoids. Recently, we have reexamined the effect of cysteine or methionine injection on the cysteine dioxygenase activity assayed by the new assay method as mentioned above. As shown in Table 3, the hepatic cysteine dioxygenase activity was also remarkably increased by the intraperitoneally injected cysteine or methionine. On the other hand, the increase of enzyme activity mediated by cysteine or methionine was not observed in adrenalectomized rat. 

Fig. 4. The effects of dietary protein on the activities of cysteine dioxygenase, cysteine desulfhydrase in liver and the urinary taurine excretion of intact rat. Plotted are cysteine dioxygenase activity(0). Cysteine desulfhydrase activity (O )> urinary taurine contents (I j). Results are expressed as the mean S.D.(represented by vertical line) of six and three animals fed on basal diet (20% protein diet) and other diets, respectively. Animals were fed on experimental diets for 2 days prior to sacrifice.

CYSTEINE. DIOXYGENASE ACITIVITY OF RAT LIVER DURING DEVELOPMENT... 

Fig. 5 summarizes the relationship between cysteine dioxygenase activity in rat liver with or without hydrocortisone injection and the hepatic cysteine contents during development. No significant activity was detected in fetal and postnatal rat liver younger than 4-day-old, and first appeared in detectable levels at the 8th postnatal day. The enzyme activity gradually increased to 13% of the adult level by 12-day-old and then markedly increased to reach the adult level at the 28th postnatal day. 

The effect of cysteine on the cysteine dioxygenase activity of 8-day-old rat liver, in which the enzyme activity was nascently induced by hydrocortisone as shown in Fig. 5, was also examined. The enzyme activity was not increased by the intraperitoneally injected cysteine(50 jig/g body weight), by which the enzyme activity in adult... 

Fig. 5. The appearance of enzyme activity and response to hydrocortisone mediated induction of cysteine dioxygenase, and the change of cysteine contents in rat liver during development. Rats were injected with hydrocortisone acetate(0.1 mg/g body weight) 25h, 20h, 15h, lOh prior to sacrifice at 2 or 4-, 8-, 12-, and over 16-postnatal-day respectively, since the time reaching the maximum induction is differ from each other depending on the age. Enzyme activity with (0) Of without(O) hydrocortisone injection. Cysteine contents in rat liver (A) Results are expressed as the mean S.D.(represent by vertical line) of five animals.

C. Loriette, H. Pasantes-Morales, C. Portemer and F. Chatagner, Dietary Casein Levels and Taurine Supplementation Effects on Cysteine Dioxygenase and Cysteine Sulfinate Decarboxylase Activities and Taurine Concentration in Brain, Liver and Kidney of the Rat, Nutr. Metab. (in press). 

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