Assuntos
Medula Óssea/efeitos dos fármacos , Cistamina/farmacologia , Eritrócitos/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Animais , Medula Óssea/metabolismo , Medula Óssea/efeitos da radiação , Contagem de Células , Citosol/metabolismo , Eritrócitos/metabolismo , Eritrócitos/efeitos da radiação , Raios gama , Hemoglobinas/análise , Masculino , Proteínas/análise , Ratos , Ratos Endogâmicos , Fatores de Tempo , Irradiação Corporal TotalRESUMO
The activity of superoxide dismutase (E.C. 1.15.1.1; SOD) was determined in male Wistar rats in order to evaluate the possible relationship between both the enzyme content in tissue and the resistance of this tissue to ionizing radiation (8,0 Gy, 60Co). Our results showed that some non-irradiated radioresistant organs (liver) had a high SOD activity and on the contrary, in some radiosensitive tissue (bone marrow) the SOD content was low. In spite of this observation it is not possible to generalize the statement that the radiosensitivity is directly conditioned by the SOD level without any exception. The SOD content in the spleen was higher than in the brain, but the spleen is remarkably radiosensitive, whereas the brain is not. The radiosensitivity of individual tissues probably reflected the changes of SOD activity after the irradiation.
Assuntos
Radioisótopos de Cobalto , Isoenzimas/metabolismo , Superóxido Dismutase/metabolismo , Irradiação Corporal Total , Animais , Medula Óssea/efeitos da radiação , Encéfalo/efeitos da radiação , Fígado/efeitos da radiação , Masculino , Ratos , Ratos Endogâmicos , Baço/efeitos da radiação , Superóxido Dismutase/sangue , Distribuição TecidualAssuntos
Eritrócitos/enzimologia , Protetores contra Radiação/farmacologia , Superóxido Dismutase/sangue , 5-Metoxitriptamina/farmacologia , Animais , Cistamina/farmacologia , Cães , Eritrócitos/efeitos da radiação , Feminino , Masculino , Lesões Experimentais por Radiação/tratamento farmacológico , Lesões Experimentais por Radiação/enzimologiaRESUMO
Changes of the total serum activity of alkaline phosphatase (AP) and its bone and intestinal isoenzymes were studied in dogs gamma-irradiated by 3.0 Gy. The activities of AP isoenzymes were determined by means of a heat inactivation-inhibition method. After irradiation the serum AP activities were lower in general. In case of the bone isoenzyme the decrease was most pronounced. The changes of the total AP activity and of the intestinal isoenzyme were less distinct. The i.m. administration of the radioprotective mixture cystamine with mexamine (24 mg/kg + 4 mg/kg) before irradiation led only to a moderate reduction of the radiation-altered AP values in the dogs. The present results indicate that the radioprotective way used here renders only an unsatisfactory protection for large laboratory animals against ionizing radiation.
Assuntos
5-Metoxitriptamina/farmacologia , Fosfatase Alcalina/sangue , Cistamina/farmacologia , Isoenzimas/sangue , Efeitos da Radiação , Triptaminas/farmacologia , Animais , Osso e Ossos/enzimologia , Cães , Feminino , Intestinos/enzimologia , Doses de RadiaçãoAssuntos
Medula Óssea/efeitos da radiação , Fígado/efeitos da radiação , Superóxido Dismutase/metabolismo , Animais , Medula Óssea/enzimologia , Contagem de Células , Citosol/enzimologia , Radicais Livres , Raios gama , Fígado/enzimologia , Masculino , Ratos , Superóxidos/metabolismo , Fatores de TempoRESUMO
The changes in the concentrations of total, nonprotein and protein SH-groups were spectrophotometrically determined in the small intestine and bone marrow of the rats 10, 20, 30 and 60 min after the administration of protective doses of cystamine (50 mg/kg), mexamine (10 mg/kg) or of a mixture of cystamine with mexamine (20 + 10 mg/kg). Cystamine caused an increase in the concentration of mainly nonprotein thiols, whereas the mexamine administration increased the protein SH-groups (mainly between the 20th and 30th min after treatment). The radioprotective mixture led to the most pronounced increase at the 10-min interval. This increase at the 10- and 20-min intervals was more pronounced (or identical) than after cystamine or mexamine administered as a single agent. If the SH-concentration should correspond to the degree of radioprotection, then the phenomenon observed would indicate the usefulness of the mixture administered.
Assuntos
Medula Óssea/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Protetores contra Radiação/farmacologia , Animais , Cistamina/farmacologia , Masculino , Ratos , Fatores de TempoAssuntos
Oxigênio/toxicidade , Animais , Bactérias/efeitos dos fármacos , Catalase/metabolismo , Células Cultivadas , Glutationa/metabolismo , Cobaias , Humanos , Peróxido de Hidrogênio/metabolismo , Peróxidos Lipídicos/metabolismo , Camundongos , Oxigênio/metabolismo , Coelhos , Ratos , Superóxido Dismutase/metabolismo , Superóxidos/metabolismoRESUMO
In the serum and the liver of rats levels of chloramphenicol (CAP) following its i.v. administration (200 mg/kg) in the control groups and in the rats irradiated with whole-body air exposure to 500 R were determined with spectrophotometric methods. The CAP-levels in the serum increased in the group of rats 3 days after irradiation, but only during the 1st hour. At later time intervals the values were lower than in the controls. This decrease at the 60th min is striking even in the groups 6 and 9 days after exposure. Free CAP in the liver of rats irradiated 6 and 9 days before was lower at interval 30 min after CAP-administration, but the group irradiated 9 days before was unaltered. However, 120 min after CAP-administration the values of free CAP decreased at all intervals investigated following the irradiation. The levels of conjugated CAP in the liver of the rats 3 and 6 days after exposure were lower than in controls in both intervals after drug administration; but in rats 9 days after irradiation they increased. Our results indicate that the kinetics of CAP is altered and corresponding changes in its conjugation are effected under the condition of acute radiation syndrome.
