Effect of urethane on insulin level in rats

AIM: In view of the contradictory reports in literatures, to further investigate effects of urethane on the plasma insulin levels in the fasting, glucose-loaded and the epinephrine-induced hyperglycemic rats. METHODS: Plasma insulin was measured with the radio-immunoassay method. RESULTS: Urethane at anesthetic dose (1.5 g · kg^-1) significantly increased the plasma insulin levels at 20 min. The plasma insulin levels increased from (11 ± 4) to (25 ± 10) mU · L^-1 (P < 0.05) in fasting rats and from (11 ± 4) to (47 ± 6) mU · L ^-1 (P < 0.01) in glucose-loaded rats at 50 min after administration of urethane. In hyperglycemic rats induced by epinephrine, urethane significantly increased the plasma insulin from (10 ± 3) to (51 ± 18) mU · L^-1 at 140 min after administration of epinephrine and urethane together. In contrast with the changes in plasma insulin levels, urethane significantly increased the blood glucose levels in fasting or glucose-loaded rats at 50 min after administration of urethane, and it did not change the hyperglycemia induced by epinephrine. CONCLUSION: Urethane increases the plasma insulin levels in the fasting, glucose-loaded and the epinephrine-induced hyperglycemic rats. Insulin secretion promoted by urethane may via both hyperglycemia-dependent and hyperglycemia-independent mechanisms.