title: Effect of dihydro-ouabain on vascular tone on the perfused cannine hindlimb.
abstract: Digitalis compounds are known to cause contraction of vascular smooth muscle. However, it has been reported by Kahn and colleagues (J. Pharmacol. Exp. Ther. 142: 215-222, 1963) that dihydro-ouabain has no effect on vascular tone in dogs. The purpose of our study was to reassess the vasoconstrictor activity of dihydro-ouabain. This was done by monitoring perfusion pressure of the canine hindlimb preparation perfused at a constant rate of blood flow and administering intra-arterial injections of dihydro-ouabain. Increasing doses of this drug (i.e., 25, 50, 100, 200 and 300 mug) produced significant dose-dependent increases in perfusion pressure. Pretreatment with phentolamine prevented the effect of dihydro-ouabain on perfusion pressure. These results indicate that dihydro-ouabain causes contraction of vascular smooth muscle by an adrenergic mechanism.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D006614:Hindlimb / Q000098:blood supply*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010042:Ouabain / Q000031:analogs & derivatives* / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D010042:Ouabain; D009638:Norepinephrine; D010646:Phentolamine