RESUMO
Althugh several studies have shown the effect of cytokines on islet B cell function, the role of circulating cells in the control of insulin secretion has not been investigated. The effect of lymphocyte administration on plasma glucose and insulin levels was examined in male Wistar albino rats weighing 180-200g. The animals were anesthetized and the jugular vein was cannulated for saline or lymphocyte injection (10**6 cells in 1 ml) and blood collection after 5, 10, 15, 20, 30, 45, and 60 min. A marked increase in plasma insulin levels (180*U/ml as compared to 56*U/ml in the control group, at 20 min) and an unexpected increase (P<0.05) in blood glucose levels (at 60 min only) were observed after lymphocyte administration. Similar experiments undertaken with simultaneous administration of inhibitors of arachidonic acid metabolism, indomethacin and nordihydroguairetic acid at 1 mg/Kg body weight, suggest that this effect of lymphocytes is not mediated by prostaglandins or leukotrienes