The effects of streptozotocin-induced diabetes and insulin-treatment on the cardiovascular system of the rat.
In this study the cardiovascular effects of diabetes consisted of a decrease in the heart rate 6 days and in the blood pressure 7 weeks after the induction of streptozotocin-diabetes in rats. The diabetes-induced decrease in heart rate was reversed within 4 days after the institution of insulin-treatment, which also prevented the fall in blood pressure. Maximal KC1 (70 mM) and phenylephrine (10(-4)M)-induced contractures in aortae from diabetic rats were 57 and 48%, respectively, of those from control animals, while tissues from insulin-treated diabetic rats did not differ from controls. Theophylline (10(-2)M)-induced relaxation of the phenylephrine contracture in diabetic tissues was less than in control aortae while relaxation of the K-contracture was greater in control than in diabetic tissues. Insulin-treatment reversed the effects of diabetes on theophylline-induced relaxation of the KC1, but not the phenylephrine contracture. These findings indicate that insulin-treatment will either prevent or reverse diabetes-induced decreases in blood pressure, heart rate and vascular responsiveness to phenylephrine and CK1.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D051381:Rats; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin