Inhibition of epinephrine-induced vasospasm with adrenoreceptor blockade in the rat cremaster muscle.

This study demonstrates that intravenous epinephrine causes arterial vasospasm, but not venous constriction, in the microcirculation of the rat cremaster muscle. This effect can be blocked by a smooth muscle relaxant such as papaverine or an alpha receptor antagonist such as phentolamine. Circulating vasospastic agents such as epinephrine are important determinants of microcirculatory blood flow, and inhibition by pharmacologic means may enhance blood flow and survival in microvascular surgery.