RESUMO
Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180 percent). Removal of the gonads in both males and females (comparison between castrated groups) increased the difference in SOD activity from 83 to 138 percent and reduced the difference in CAT activity from 180 to 86 percent. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48 percent) CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle
Assuntos
Animais , Feminino , Ratos , Antioxidantes/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Oxirredutases/metabolismo , Castração , Catalase/metabolismo , Estrogênios/farmacologia , Glutationa Peroxidase/metabolismo , Macrófagos Peritoneais/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Caracteres Sexuais , Superóxido Dismutase/metabolismo , Testosterona/farmacologiaRESUMO
Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%). Removal of the gonads in both males and females (comparison between castrated groups) increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48%) CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.
Assuntos
Antioxidantes/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Oxirredutases/metabolismo , Animais , Castração , Catalase/metabolismo , Estrogênios/metabolismo , Feminino , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Macrófagos Peritoneais/enzimologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Caracteres Sexuais , Superóxido Dismutase/metabolismo , Testosterona/farmacologiaRESUMO
Magnetic resonance was used to investigate the kinetic disposition of magnetite nanoparticles (9.4 nm core diameter) from the blood circulation after intravenous injection of magnetite-based dextran-coated magnetic fluid in female Swiss mice. In the first 60 min the time-decay of the nanoparticle concentration in the blood circulation follows the one-exponential (one-compartment) model with a half-life of (6.9 +/- 0.7) min. The X-band spectra show a broad single line at g approximately 2, typical of nanomagnetic particles suspended in a nonmagnetic matrix. The resonance field shifts toward higher values as the particle concentration reduces, following two distinct regimes. At the higher concentration regime (above 10(14) cm(-3)) the particle-particle interaction responds for the nonlinear behavior, while at the lower concentration regime (below 10(14) cm(-3)) the particle-particle interaction is ruled out and the system recovers the linearity due to the demagnetizing field effect alone.