Effect of dietary protein deficiency on rat hepatic drug-metabolizing enzyme system.
We have examined the effect of dietary protein deficiency on rat hepatic drug-metabolizing enzyme system for a period of two months. Cytochrome P-450 and b5 contents in liver microsomes, which were plotted on semilogarithmic paper as a function of the time of deficiency, showed biphasical reductions during protein deficiency: rapid decreases in the first 3 weeks were followed by more gradual decreases. However, the three enzymatic activities examined, i.e. aminopyrine demethylase, aniline hydroxylase and p-nitroanisole demethylase, were not reduced at a uniform rate. In the earlier phase, activities of the former two enzymes were reduced more rapidly than that of the last phase. This biphasical and non-uniform reduction of enzymatic activities suggests the existence of two or more cytochrome P-450 subspecies in non-depleted male rats. Intraperitoneal administration of well-known environmental pollutants, polychlorinated dibenzofurans and biphenyls (100 micrograms and 100 mg/kg, respectively) to the depleted rats resulted in a marked induction of drug-metabolizing enzymes. However, as the deficiency became more severe (2 months), the induction declined to a considerable degree, especially in the case of polychlorinated biphenyl administration.
D000633:Aminopyrine N-Demethylase / Q000096:biosynthesis / Q000378:metabolism; D000815:Aniline Hydroxylase / Q000096:biosynthesis / Q000378:metabolism; D000818:Animals; D001572:Benzofurans / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D001835:Body Weight / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D009575:Nitroanisole O-Demethylase / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011488:Protein Deficiency / Q000201:enzymology*; D051381:Rats
D001572:Benzofurans; D001713:Biphenyl Compounds; D003577:Cytochrome P-450 Enzyme System; D009575:Nitroanisole O-Demethylase; D000815:Aniline Hydroxylase; D000633:Aminopyrine N-Demethylase