TY - JOUR T1 - THE DIRECT EFFECTS OF VASOACTIVE AGENTS ON PULMONARY VEINS. STUDIES OF RESPONSES TO ACETYLCHOLINE, SEROTONIN, HISTAMINE AND ISOPROTERENOL IN INTACT DOGS JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 96 LP - 105 VL - 168 IS - 1 AU - ALBERT L. HYMAN Y1 - 1969/07/01 UR - http://jpet.aspetjournals.org/content/168/1/96.abstract N2 - In the intact dog a catheterization technique, designed to measure vascular pressures and blood volume in a hemodynamically separated lobe perfused at a constant rate of flow, was used to study the active responses of pulmonary veins to small volume infusions of vasoactive compounds. These active responses were compared to simultaneously occurring modulated responses in the other lobes which were normally perfused. These data indicate that serotonin actively constricts both the lobar arteries and veins but suggest that the more gradually active venoconstriction may modulate the more abruptly active constriction of the upstream vessels. Acetylcholine and histamine actively constrict the lobar small veins. Less direct evidence suggests that acetylcholine constricts the lobar arteries as well, but any tendency for histamine to constrict the lobar arteries is obscured by the accompanying venoconstriction. The data indicate that isoproterenol actively dilates the lobar small veins and suggest an active dilation in the lobar arteries. No active responses of larger pulmonary veins near the venoatrial junction were detected. © 1969, by The Williams & Wilkins Company ER -