RESUMO
When the litters were 14 days old, wistar rat pups received lead ions. The suckling mother was fed by a powdered laboratory chow containing lead carbonate (1%, 2%, 4%). The intoxication was going on for 3 days to 9 weeks. While lead-fed pups showed a decrease in body-weight gain and in neurologic development, lead ions were without effects on oxygen consumption, ADP-phosphorylation and activity of several enzymes of cerebral mitochondria. On the other hand, the important lead accumulation into cerebral mitochondria was in a straight ratio with lead doses in the feedings. To explain the in vivo data, the effects of lead acetate were investigated in vitro on brain mitochondria of young male wistar rats. Our findings indicate that lead ions alter mitochondrial respiration and ADP-phosphorylation and that inorganic phosphate has a protective effect.
Assuntos
Encéfalo/efeitos dos fármacos , Intoxicação por Chumbo/complicações , Mitocôndrias/efeitos dos fármacos , Compostos Organometálicos , Animais , Encéfalo/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Chumbo/análise , Chumbo/farmacologia , Mitocôndrias/metabolismo , NADH Desidrogenase/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Fósforo/farmacologia , Fósforo/fisiologia , Ratos , Ratos Endogâmicos , Succinato Desidrogenase/metabolismo , Fatores de TempoRESUMO
Rats were treated with MnSO4, H2O (1 mg/100 g/day, SC) for a period of 5 weeks. Thyroxine (T4) and triiodothyronine (T3) levels were measured in thyroid by radioimmunoassay. T4, T3 and thyroid-stimulating hormone (TSH) levels were also estimated by radioimmunoassay in serum. Manganese treatment produced no change in thyroid T4 and T3 levels but induced a significant decrease in serum T4, T3 and TSH levels. This decrease can be interpreted as the result of a pituitary alteration which appears to be related to the high accumulation of manganese in the pituitary gland.
Assuntos
Manganês/farmacologia , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/sangue , Animais , Manganês/análise , Radioimunoensaio , Ratos , Ratos Endogâmicos , Glândula Tireoide/análise , Distribuição TecidualRESUMO
Injection into rats of manganous chloride (2 mg/100 g) showed, after a 24-hr period, a marked depression of thyroidal 131I uptake. There is a decrease in serum T3 and T4 levels and an increase in I- level. These results demonstrate that the action of manganous ions is to block uptake of I- by the thyroid.
