THE EFFECTS OF STREPTOZOTOCIN-INDUCED DIABETES AND INSULIN-TREATMENT ON THE CARDIOVASCULAR-SYSTEM OF THE RAT

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  • 1 January 1980
    • journal article
    • research article
    • Vol. 28  (1) , 27-41
Abstract
The cardiovascular effects of diabetes consisted of a decrease in the heart rate 6 days and in the blood pressure 7 wk 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 KCl (70 mM) and phenylephrine [PE] (10-4M)-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 (10-2M)-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 KCl, but not the PE contracture. Insulin-treatment will apparently prevent or reverse diabetes-induced decreases in blood pressure, heart rate and vascular responsiveness to phenylephrine and KCl.