RESUMO
We have studied the effect of 3-nitrobenzothiazolo(3,2-a)quinolinium (NBQ) on the regeneration of the lens in adult newt Notophthalmus viridescens. NBQ has marked cytotoxic effects in tumor cells, intercalates DNA, and was found to enhance lens regeneration. Newt liver DNA was isolated, and the thermal denaturation temperature (Tm) determined to be 76.6% +/- 0.8%. The G-C content was determined to be 44.0% +/- 0.4% and 45.0% +/- 0.1%. Parameters of NBQ binding to newt DNA were determined by spectrophotometric methods and compared with those obtained for calf thymus and Micrococcus lysodeikticus. The association constant, K(o), was found to be 1.1 x 10(+5) M-1 with a site-size parameter, n, of 8.7 nucleotides. No explanation is apparent for the paradoxical stimulation of lens regeneration.
Assuntos
Antineoplásicos/farmacologia , DNA/metabolismo , Substâncias Intercalantes/farmacologia , Cristalino/efeitos dos fármacos , Compostos de Quinolínio/farmacologia , Regeneração/efeitos dos fármacos , Animais , Antineoplásicos/metabolismo , Substâncias Intercalantes/metabolismo , Cristalino/fisiologia , Notophthalmus viridescens , Compostos de Quinolínio/metabolismo , Espectrofotometria Ultravioleta , TemperaturaAssuntos
Sistema Imunitário/fisiologia , Esplenectomia , Animais , Infecções Bacterianas/etiologia , Sobrevivência de Enxerto , Transplante de Coração , Homeostase , Humanos , Doenças do Sistema Imunitário/etiologia , Transplante de Rim , Linfócitos/fisiologia , Masculino , Neoplasias/etiologia , Doenças Parasitárias/etiologia , Complicações Pós-Operatórias , Ratos , Transplante de Pele , Baço/anatomia & histologia , Baço/citologia , Baço/imunologia , Baço/fisiologia , Esplenectomia/efeitos adversosRESUMO
The effect of splenectomy on animals infected with Trypanosoma lewisi is unclear, and previous reports are inconclusive or conflictive. We splenectomized rats of different ages after they had been infected with T. lewisi. Female Sprague-Dawley rats, Hemobartonella-free, were assigned to four groups according to weight: 80, 108, 140, and 170 g. Each group had splenectomized, sham-operated, and nonoperated control subgroups, all infected with T. lewisi (0.5 ml of 10(6) parasites per ml) 90 h before surgery. Before surgery, parasite levels in host blood were similar. At 24 h after splenectomy in all groups, regardless of weight, blood parasite levels were much higher than they were in sham-operated or control animals (P less than 0.001 to P less than 0.0001; analysis of variance). Younger rats (80 and 108 g) had a higher mortality rate after splenectomy than sham-operated and control animals. Older rats (150 and 170 g) had no mortality. These results show the impact of age and the importance of the spleen on parasite-host interactions in rats infected with T. lewisi.
