The effects of glyburide and insulin on the decreased beta-adrenergic responsiveness of the gastrointestinal tract in rats with non-insulin-dependent diabetes.
1. Decreased beta-adrenergic responses have been reported in gastro-intestinal tract of rats with diabetes mellitus. Effects of glyburide and insulin on the decreased beta-adrenergic responsiveness of the gastro-intestinal tract due to non-insulin-dependent diabetes were investigated using duodenum, jejunum and ileum from rats which were injected with alloxan in their neonatal periods. 2. Insulin treatment of non-insulin-dependent diabetic rats for 10 days corrected the decreased beta-adrenergic responses of the isolated duodenum, jejunum and ileum confirming the previous results obtained from insulin-dependent diabetic rats. 3. Glyburide treatment alone for 3 weeks also reversed the changes in the gastro-intestinal beta-adrenergic responses of non-insulin-dependent diabetic rats. Combination of glyburide with insulin, however, did not cause an additive or supra-additive interaction in terms of beta-adrenergic sensitivities of the diabetic tissues. 4. The results obtained in the present study strongly suggested that non-insulin-dependent diabetes may cause a decrease in the number of gastro-intestinal beta-adrenoceptors, while glyburide and insulin treatments correct the changes related to beta-adrenoceptors. The effect of insulin on the beta-adrenergic sensitivity of diabetic rat duodenum, jejunum and ileum may occur via a direct mechanism, whereas glyburide seems to be effective on the beta-adrenergic responses through the increases in the insulin secretion and/or in the number of gastro-intestinal insulin receptors.
Oztürk
Y
Y
Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Tepebaşi, Eskişehir, Turkey.
Yildizoğlu-Ari
N
N
Ozüari
A
A
Altan
V M
VM
D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D004064:Digestive System / Q000187:drug effects* / Q000648:ultrastructure*; D004386:Duodenum / Q000187:drug effects / Q000648:ultrastructure; D005905:Glyburide / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*
D001786:Blood Glucose; D007328:Insulin; D011943:Receptors, Adrenergic, beta; D000420:Albuterol; D005905:Glyburide