Arterial Wall "Waterlogging" Accompanying Chronic Digoxin Treatment in Dogs

Publisher Website
Google Scholar
Abstract
To chronically decrease activity of the ouabain-sensitive Na pump in vascular smooth muscle digoxin (60 .mu.g/kg, followed by 8-16 .mu.g/kg per 12 h i.v.) was administered to 5 male mongrel dogs for 4 wk. Serum digoxin levels were monitored and maintained at concentrations sufficient to continuously inhibit the Na pump. Blood pressures and serum Na+ and K+ concentrations of the treated dogs did not change significantly. Five paired control dogs received saline injections. At 2 h after a final injection, samples of small mesenteric arteries and veins were obtained under sodium pentobarbital (30 mg/kg i.v.) anesthesia for measurement of vessel wall 86Rb uptake and water content. In veins there were no significant changes in pump activity or water content. In arteries the ouabain-sensitive 86Rb uptake was depressed (P < 0.02) in treated dogs. Accompanying this depression was an increase, averaging 6.2% (P < 0.05), in mesenteric artery wall water content. Chronic digitalis suppression of the Na pump in arteries may be associated with the development of wall edema. Inhibition of the sarcolemmal Na pump of arteries may underlie the waterlogging of these vessels in hypertension.