Relationship between untreated and insulin-treated diabetes and vascular relaxation.

The effects of untreated and insulin-treated streptozotocin-induced diabetes on the ability of the rat aorta maximally contracted with either 10(-4) M phenylephrine (PE) or 70 mM KCl to relax in response to 10(-5) to 10(-2) M theophylline (Theo) were examined. No significant differences between Theo-induced relaxation of the PE-contracture in control, untreated diabetic and insulin-treated diabetic aortas were observed until 12 weeks after the induction of diabetes. Twelve weeks after the induction of diabetes, the untreated diabetic aortas exhibited less relaxation in response to Theo than did the controls.

The effects of fructose-1,6-diphosphate on the isolated rabbit heart.

The effects of 0.1-100 mgm of fructose-1,6-diphosphate (FDP) were observed on the inotropic and chronotropic activity of the isolated, perfused rabbit heart, using a modified Langendorff technique. The preparations were treated with bolus injections of 0.

Insulin reversal of diabetes-induced inhibition of vascular contractility in the rat.

Contractures induced by 10(-9)-10(-4) M phenylephrine (PE) or 10-70 mM KCl were observed in aortas isolated from untreated and insulin-treated streptozotocin-diabetic rats. The experiments were conducted at 2-wk intervals for a 12-wk period after the induction of diabetes. Diabetes caused an average decrease of 58 and 60% in the K and PE contractures, respectively.

Contractile and relaxing activity of arterial smooth muscle from streptozotocin-diabetic rats.

Contractures induced by 10(-4)M phenylephrine (PE) and 70 mM KCl and their relaxation by 10(-2) M theophylline (theo) were observed in aortae isolated from untreated and insulin-treated streptozotocin-diabetic rats for 12 weeks after the induction of diabetes. Diabetes consistently caused an average decrease of 40% in the PE and K-contractures. Treatment of diabetic animals with 2.

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.