RESUMEN
Lycopene produced by recombinant Escherichia coli was tested for subacute oral toxicity to determine its No-Observed-Adverse-Effect Level (NOAEL). Doses of 0, 200, 500 and 2000 mg/kg body weight/day were administered daily by gavage to 10 rats/sex/group for 28 days. No statistically significant, dose-related effect on body weight gain, clinical signs or ophthalmoscopic parameters was observed in any treatment group. Likewise, no treatment-related or dose-related toxic effect was found in hematology, clinical chemistry, urinalysis, blood coagulation, organ weight, gross observation or histopathology. Thus, the NOAEL for lycopene derived from recombinant Escherichia coli was at least 2000 mg/kg body weight/day.
Asunto(s)
Antioxidantes/toxicidad , Carotenoides/toxicidad , Escherichia coli/metabolismo , Administración Oral , Animales , Antioxidantes/administración & dosificación , Peso Corporal/efectos de los fármacos , Carotenoides/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Licopeno , Masculino , Nivel sin Efectos Adversos Observados , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Pruebas de Toxicidad/métodosRESUMEN
We described previous that the adrenal medulla recovers rapidly from the injuries due to salinomycin. In the present study we found the recovery to be apparently due to differentiation of pre-existing, primitive undifferentiated, chromaffin cells, rather than mitosis, as evidenced by lack of incorporation of 5-bromo-2-deoxyuridine in the differentiating and/or differentiated chromaffin cells. Electron-dense, striated fibrils observed within the necrotic cells and in the extracellular space were presumed to be intermediate degradation products. Schwann cells actively functioned as phagocytes in this study, and seemed to indirectly stimulate the differentiation of undifferentiated chromaffin cells.