CALCIUM DEPENDENCE OF NOREPINEPHRINE-INDUCED VASCULAR CONTRACTION IN EXPERIMENTAL DIABETES

Google Scholar
  • 1 January 1980
    • journal article
    • research article
    • Vol. 212  (2) , 253-258
Abstract
Changes in the contractile responses to norepinephrine [NE] of aortas obtained from streptozotocin-induced diabetic rats were studied and the effects of changes in extracellular Ca2+ concentrations on those contractile responses determined. Aortic rings from rats diabetic 14-20 days were supersensitive to NE in 0.20, 0.40 and 0.80 mM Ca2+, but not in 2.50 mM Ca2+. Aortas from rats diabetic 28-35 days showed a marked increase in contractile force to NE in 0.20, 0.40, 0.80 and 250 mM Ca2+. The contractile force was significantly greater in the 28-35 day diabetic group as compared to the 14-20 day diabetic group. When the Ca2+ concentration was changed from 2.50 mM to 0.20 and 0.40 mM, the aortas from the 28-35 days diabetic rats showed a significant decrease in developed tension. Vascular reactivity is altered in experimental diabetes, and this change is due to the duration of the diabetic state and to the extracellular Ca2+ concentration.