Alpha-adrenoceptor blockade by tibalosine: hemodynamic and humoral effects at rest and during exercise, and effect of opioid receptor antagonism.

Summary:In a randomized double-blind protocol, 12 healthy male volunteers were studied twice at rest and during exercise after pretreatment for 1 week with placebo or 150 mg daily of the new α1-adrenoceptor antagonist tibalosine. Six subjects received, on both experimental days, an intravenous infus