Effect of epinephrine, norepinephrine and serotonin upon systemic small and large vessel resistance.

IN' 1952, Hackly, Richards and Visscher 1 noted that instantaneous brachial artery injections of commercial epinephrine, 1-epinephrine bitartrate and 1-norepinephrine bitartrate monohydrate in 0.5-5.0 y doses elevated dog forepaw small artery and vein pressures, decreased foreleg blood flow rate and did not change foreleg large vessel pressures. Serotonin creatinine sulfate in the same amounts decreased small artery pressure, increased small vein pressure and did not greatly change large vessel pressures or blood flow rate. The methods employed, however, did not permit a precise analysis of changes in vascular geometry. These data were only reported in part in abstract form. The present report concerns a reinvestigation of the above problem utilizing improved methods. Studies have separately been made of changes in the geometric component of resistance of the dog foreleg arteries, veins and small vessels and these changes have been compared between epinephrine, norepinephrine and serotonin.