Cardioprotective effect of glutathione in isoproterenol - induced myocardial necrosis in albino rats

The present study was designed to investigate the cardioprotective effect of oral administration of reduced glutathione [GSH] in the isoproterenol [ISO]-induced cardiac lesions in rats; an animal model for myocardial infarction in man. Eighteen adult male albino rats were randomly allocated into 3 groups; each of 6 rats. Rats of control group were subcutaneously injected daily with 2 ml normal saline on days 14 and 15. Rats of ISO group were subcutaneously injected with isoproterenol hydrochloride [Lab. Renaudin, France] with a daily dose of 85 mg/kg body weight [b.wt.] on days 14 and 15. Rats of ISO/GSH group received orally GSH with a daily dose of 500 mg/kg. b.wt. for fifteen days. In addition, animals of ISO/GSH group were injected with ISO with the same regimen as mentioned in ISO group. On day 16, all animals were sacrificed and the hearts were excised and processed for histological and immunocytochemical microscopic examinations. The results of the present study confirmed the ISO-induced myocardial lesions including cardiomyocyte necrosis accompanied by mononuclear inflammatory cells infiltration, interstitial edema as well as mild increase of collagen fibers. Administration of reduced glutathione with and before ISO injections markedly prevented almost all of these changes. These findings proved that oral administration of reduced glutathione exerts a strong cardioprotective effect in ISO-induced cardiac damage in rats

Effect of cyclosporin [A] administration and withdrawal on the mesenteric lymph nodes in albino rats

The present study investigated the histological changes induced in the mesenteric lymph nodes of albino rats by short-term cyclosporin A [CsA] administration and to determine the reversibility of these changes after CsA withdrawal. Eighteen adult male albino rats were randomly allocated into 3 groups; each of 6 rats. Control rats received a daily subcutaneous [s.c.] injection of olive oil at a dose of 1 ml/kg body weight [b.wt.] for 5 days. Control rats were sacrificed either 24 hours or one week after the last injection. Rats from CsA-treated group received a daily s.c. injection of CsA at a dose of 15 mg/kg b.wt. for 5 days. Rats were sacrificed 24 hours after the last injection. Rats from CsA-withdrawal group received a daily s.c. injection of CsA at a dose of 15 mg/kg b.wt. for 5 days. Rats of this group were sacrificed one week later. The results showed that CsA administration induced decreased cellularity of the mesenteric lymph nodes with decrease of CD3 positive T cells, CD57 positive cells and CD20 positive B cells. In contrast, CD68 positive macrophages increased. The germinal centers of lymphoid follicles were enlarged with a thin mantle. Numerous tingible-body macrophages were found in the germinal centers with multiple apoptotic bodies giving the starry-sky appearance of the germinal centers of the follicles. These histological changes showed regression or complete resolution with withdrawal of CsA administration