Effects of Epinephrine on the Vessels of the Calf. Observations on the Period of Initial Vasodilatation

Abstract

[long dash]Epinephrine given intraven. or intra-arterially by single injn. or by continuous infusion causes immediate short-lived vasodilatation in the calf. This cannot be sustained by repeated injns. of epinephrine. It is caused by a sudden change in rate of admn. of epinephrine and is not dependent on the absolute rate of injn. This initial vasodilatation is not accompanied by an increase in the lactic acid or K concns. of femoral blood. There is no rise in arterial K level. The arteriofemoral venous O2 difference decreases to half of the preinjection level. At the time of this initial vasodilation in the calf, the vessels of the foot are constricted. As judged by arteriointernal jugular O2 differences, the vessels of the brain are not dilated. Observation on the arteriohepatic venous O2 differences are inconclusive.