RESUMO
The effect of isatin (indole-2,3-dione) on D-glucose uptake has been studied in rat intestine. Isatin at 6 mM concentration significantly inhibited both the sugar uptake and transmural (mucosal to serosal side) transport in the intestine. The suppression of glucose uptake by isatin was irreversible. Similar to the action of various SH-group-reacting agents, isatin inhibited the sugar uptake, presumably by binding to membrane sulfhydryl groups through a covalent linkage. Isatin-induced reduction in glucose uptake was unaffected by pH (between 5.5 and 8.4) and by DTT addition to incubation medium. Inhibition of sugar uptake by isatin and harmaline was additive in nature; this suggested that these compounds interact at different sites on the microvillus membrane surface.
Assuntos
Alcaloides/farmacologia , Glucose/metabolismo , Harmalina/farmacologia , Indóis/farmacologia , Absorção Intestinal/efeitos dos fármacos , Isatina/farmacologia , Reagentes de Sulfidrila/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Masculino , Ratos , Ratos EndogâmicosRESUMO
Effect of depot medroxyprogesterone acetate on the hepatic drug-metabolizing enzymes was studied in female protein-deficient and normal pair-fed rats. Treatment with this drug did not cause any change in organ weight, microsomal protein, and soluble protein yield per gram of tissue in both groups. MPA administration resulted in significant increases in the content of cytochrome P-450 and b5, and activities of benzo[a]pyrene hydroxylase, UDP-glucuronosyltransferase, and NADPH-Cyt c reductase in both pair-fed control and protein-deficient rats. However, the content of glutathione and activity of glutathione-S-transferase were not affected appreciably. The present study suggests that MPA treatment induces drug-metabolizing enzymes in liver to almost the same extent in both protein-deficient and normal pair-fed rats.