The effects of glyburide and insulin on the cardiac performance in rats with non-insulin-dependent diabetes mellitus.
1. The effects of glyburide were studied on the myocardial contractile force and heart rate in the atria isolated from non-diabetic and non-insulin-dependent diabetic rats (diabetic). 2. In order to examine the myocardial changes in the alloxan model of non-insulin-dependent diabetes, atrial functions of 11-week old diabetic rats were evaluated by comparing with the atria from their age-matched controls. 3. Diabetic atria were found to possess an increased contractile force and reduced inotropic responses to isoprenaline as a consequence of non-insulin-dependent diabetes induced by neonatal alloxan injection. 4. However, no significant change was observed in the heart rate of diabetic atria in response to isoprenaline when compared with controls. 5. Since apparent affinity constant (pD2 value) calculated for the inotropic response of diabetic atria to isoprenaline was also reduced, it might be suggested that non-insulin-dependent-diabetes causes a decrease in the beta-adrenoceptor affinity of the rat atria. 6. Glyburide treatment (5 mg/kg/day per os) for 3 weeks was able to improve the reduced responsiveness of rat atria due to non-insulin-dependent diabetes as well. The results obtained in this study indicated that glyburide possesses an improving effect on the decreased beta-adrenergic responses of rat atria with non-insulin-dependent diabetes mellitus.
Ozüari
A
A
Ankara University, Faculty of Pharmacy, Department of Pharmacology, Turkey.
Oztürk
Y
Y
Yildizoğlu-Ari
N
N
Ozçelkay
A T
AT
Altan
V M
VM
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D004327:Drinking Behavior / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D005905:Glyburide / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D014554:Urination / Q000187:drug effects
D001786:Blood Glucose; D007328:Insulin; D007545:Isoproterenol; D005905:Glyburide