Premium
Effects of dopexamine hydrochloride, a beta‐adrenergic and dopaminergic agonist, on vascular resistances, and flow distribution between cutaneous and skeletal muscle vasculatures
Author(s) -
Grega George J.,
Staniciu Dorina,
Murray Melissa,
Lokhandwala Mustafa F.
Publication year - 1991
Publication title -
drug development research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.582
H-Index - 60
eISSN - 1098-2299
pISSN - 0272-4391
DOI - 10.1002/ddr.430220107
Subject(s) - vasodilation , skeletal muscle , forelimb , vascular smooth muscle , perfusion , vascular resistance , medicine , agonist , anatomy , chemistry , endocrinology , hemodynamics , receptor , smooth muscle
Local i.a. infusions of the dopaminergic and β 2 adrenoceptor agonist dopexamine HCL (DPX) into collateral‐free, innervated canine forelimbs perfused at constant flow produced dose‐dependent decreases in perfusion pressure, evidence of a vasodilator response in the forelimb vasculature. DPX produced vasodilation in both the skin (cutaneous) and skeletal muscle vasculature of the canine forelimb, as evidenced by the dose‐dependent decrease in total skin and total skeletal muscle vascular resistances. DPX produced comparable dilation of the skin and skeletal muscle vasculatures, as evidenced by the failure of this agent to produce a significant shift in blood flow between the brachial and cephalic venous outflows, that is, between the skin and skeletal muscle vasculatures. In the cutaneous (skin) vascular circuit, DPX failed to affect vascular resistances in the large artery and large vein segments, but produced a dose‐dependent decrease in vascular resistance in the small vessel segment, presumably reflecting primarily arteriolar vasodilation. The vascular smooth muscle relaxation produced by DPX was inhibited by treatment with propranolol, suggesting that the vasodilation primarily results from direct stimulation of forelimb vascular β 2 adrenoceptors by DPX.