Effects of morphine sulfate on NADPH-cytochrome c reductase and cytochrome P-450 of mouse liver microsomes.
Three hr after i.p. administration of a single dose of 30 mg/kg of morphine to male mice, an increase in specific activity of NADPH-cytochrome c reductase by about 10% and the content of cytochrome P-450 by about 14% of their liver microsomes was observed.Administration of 30 mg/kg of morphine, once daily,during 5 days, caused about 16% and 9% increases in specific activity of c reductase and the content of P-450 respectively. Administration of a single dose of morphine to male and female mice caused no sex-dependent differences in the specific activity of c reductase and the content of P-450. Repeated administration of morphine up to 100 mg/kg to male mice increased the specific activity of microsomal c reductase by about 70%. Repeated administration of morphine up to 55 mg/kg also increased the microsomal content of P-450 by about 22%, but with higher doses of morphine, the content of P-450 declined and finally dropped below control levels. The levels of c-reductase activity and P-450 content returned to normal levels about 2 weeks after termination of morphine administration.
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003579:Cytochrome Reductases / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D009020:Morphine / Q000494:pharmacology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism*; D013997:Time Factors
D009020:Morphine; D003577:Cytochrome P-450 Enzyme System; D003579:Cytochrome Reductases; D009251:NADPH-Ferrihemoprotein Reductase