Evidence for increased functional vascular Na+/K+ pump activity in the obese Zucker rat.

Insulin is known to stimulate Na+/K+ ATPase and to relax vascular smooth muscle. We hypothesized that vascular tone in the obese Zucker (fa/fa) rat, a hyperinsulinemic model in which hypertension can develop, may be influenced by insulin's ability to stimulate Na+/K+ ATPase at the vascular level. We studied isometric preparations of tail and femoral arteries from 10-wk-old, male obese Zucker rats, which were hyperinsulinemic but still normotensive vs.