RESUMO
To examine the role of multiple forms of cytochrome P-450 in the metabolism of endogenous substrates by lung, the oxidation of testosterone by rat lung microsomes in vitro was characterized and compared to liver. In lung, the majority of metabolism took place at the 16-position, with minor metabolism at the 15 alpha- and 2 beta-positions. Metabolism by lung was up to 200-fold less than liver and, unlike liver, was not sexually differentiated. Although under different regulatory control, similar forms of cytochrome P-450 may contribute to the hydroxylation of testosterone by rat lung and liver.
Assuntos
Pulmão/metabolismo , Microssomos/metabolismo , Testosterona/metabolismo , Animais , Feminino , Técnicas In Vitro , Masculino , Microssomos Hepáticos/metabolismo , Oxirredução , Proteínas/metabolismo , Ratos , Ratos Endogâmicos F344RESUMO
A commercially prepared semipurified diet (Bio-Serve No. 0006Q) composed of chemically defined ingredients was fed to male and female F344 rats before mating, to females during gestation, and to the offspring after weaning. Compared to rats treated similarly but fed a standard, cereal-based chow (Agway CR RMH 3000), offspring on the semipurified diet exhibited markedly retarded growth. At 12 weeks of age, the deficits in body weight were accompanied by decreased absolute organ weights, increased organ-to-body weight ratios, increased serum cholesterol and triglyceride levels, and development of hepatic periportal lipidosis in both male and female offspring on the semipurified diet. The deficits in body weight are explained, in part, by decreased intake of the semipurified diet, most likely attributable to its high sucrose content. Investigators are cautioned about the inadequacy of certain semipurified diets for development and postnatal growth of F344 rats.
