The study suggests that increased vascular resistance in hypertensive rats is driven by structural changes and cellular hyperreactivity involving excitation-contraction coupling.
Vascular resistance of the perfused whole body and isolated hindquarters was increased using preparations from renal, deoxycorticosterone/NaCl and genetic hypertensive rats. An increased reactivity to injected noradrenaline was observed in isolated perfused hindquarters from all three types of hypertensive rats. In depolarized mesenteric artery preparations, the calcium dose-response curves in preparations from normotensive and hypertensive rats were similar. The results point to structural changes of the blood vessels and a cellular hyperreactivity involving the process of excitation-contraction-coupling.
Finch et al. (Thu,) studied this question.