A STUDY OF FLOW AND PATTERN RESPONSES IN PERIPHERAL ARTERIES TO THE INJECTION OF VASOMOTOR DRUGS

Publisher Website
Google Scholar
Abstract
Optically recorded flow patterns (with an improved orifice-type meter) together with the coexisting pressure pulses in the superior mesenteric, hepatic, renal, common carotid, axillary, and femoral arteries of anesthetized dogs are presented. The effects of intra-arterial and intravenous adm. of vasodilator and constrictor drugs on the flow and pressure curves are shown. Following the system of analysis previously described, several series of curves were examined with reference to changes in 1, mean flow; 2, relationship of mean flow to mean pressure; 3, similarity of contour between patterns and pressure pulses; 4, vol. of pulsatile deviation from the mean rate of flow (dynamic volume-elastic properties of the vascular tree), and 5, the vasomotor state of the bed (dilatation or constriction). The generally accepted vasomotor responses to so-called dilator and constrictor drugs given intra-arterially were observed. However, in some records, and especially in those obtained following intravenous drug adm., changes in the vasomotor state of the bed could not be detd. be- cause of the overlapping of central and peripheral drug effects. The dynamic vol.-elastic component is reduced, except in the common carotid artery, by vasoconstrictor drugs given intra-arterially, while vasodilators usually increase this fraction during most of the period of drug action. The inj. of constrictor drugs, either intravenously or intra-arterially, may cause the appearance or augmentation of back flow in the patterns of all peripheral arteries so far studied. Dilators may introduce back flow in the common carotid pattern and greatly augment that preexisting in the common carotid, axillary, and femoral arterial patterns. The interrelationship of the determinants associated with vasomotor drug effects is considered and discussed.