Glutamine or whey-protein supplementation on alloxan-induced diabetic rats. Effects on CD4+ and CD8+ lymphocytes1 Efeitos da oferta de glutamina ou de proteína do soro de leite sobre os linfócitos CD4+ e CD8+ em ratos diabéticos aloxano induzidos

Purpose: To evaluate the effects of glutamine (L-Gln) or whey-protein supplementation on CD4+ and CD8+ lymphocytes in alloxan-induced diabetic rats. Methods: Thirty-two healthy male Wistar rats were used in the experiment. Eight rats served as baseline controls (G-1). The remaining 24 animals received alloxan 150mg/Kg intraperitonially dissolved in buffer solution and were equally distributed in 3 subgroups, upon induction of diabetes mellitus, and treated as follows: (G2): saline, 2.0ml; (G3): glutamine solution (0.7g/kg), 2.0 ml; and (G4): whey-protein (WPS) solution (0.7g/kg), 2.0 ml. All solutions were administered by daily 7:00 AM gavages during 30 days. Next, arterial blood samples (3.0 ml) were collected from anesthetized rats for CD4+ and CD8+ lymphocyte count through flow cytometry technology. Results: CD4+ and CD8+ counts decreased significantly in all groups compared with baseline values (G1). G2 rats CD4+/CD8+ ratio decreased significantly compared with G1. CD4+/CD8+ ratio increased significantly (>260%) in L-Gln treated group (G3) compared with saline-treated rats (G2). There were no statistical differences in lymphocyte counts (CD4+ and CD8+) between L-Gln (G3) and saline-treated (G2) groups. There was a significant reduction in CD8+ cell count compared with CD4+ cell count in L-Gln treated rats (G3). Conclusion: The offer of L-Gln to experimental diabetic rats enhances the immunologic response to infection.