The effect of succinic acid monomethyl ester (SAM) on the responses of isolated thoracic aorta in streptozotocin-diabetic rats.
Succinic acid monomethyl ester (SAM) was recently proposed as an insulinotropic tool in non-insulin-dependent diabetes mellitus. The present study was designed to define whether SAM has the vascular effect in thoracic aorta of streptozotocin (STZ)-diabetic rats. (1) Body weights of diabetic rats were significantly increased after SAM treatment (P < 0.05). (2) Ten-day SAM treatment did not significantly affect blood glucose levels in SAM-treated control and SAM-treated STZ-diabetic rats. (3) Maximum tension responses to noradrenaline and KCl (80 mmol l-1) were not significantly different among all the experimental groups. (4) pD2 (-log EC50) values for noradrenaline of untreated diabetic rats were significantly less than those of controls, SAM-treated control and SAM-treated diabetic rats (P < 0.01, P < 0.001 and P < 0.05, respectively). SAM treatment normalized the decreased sensitivity of noradrenaline response in diabetic rats. (5) Fast, slow and total components of responses to noradrenaline (10(-5) mol l-1 approximately equal to EC90) were not significantly different among all the experimental groups. (6) There were no significant differences between aorta precontracted with noradrenaline from controls and STZ-diabetic (untreated and SAM-treated) rats in pD2 values and the potency of maximum relaxation to acetylcholine or in pD2 values to sodium nitroprusside. In conclusion, 10-day SAM treatment increases the sensitivity of diabetic-aortic rings to noradrenaline compared to untreated diabetic control rats.
Department of Pharmacology, Cerrahpasa Faculty of Medicine, University of Istanbul, Turkey.
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D000704:Analysis of Variance; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013386:Succinates / Q000494:pharmacology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D013386:Succinates; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C041105:monomethyl succinate