Influence of triiodothyronine on the contractile effect of D-nor-pseudoephedrine.

Here we contrast the vascular smooth muscle contractility produced by D-nor-pseudoephedrine, alone or combined with triiodothyronine, on the aorta and coronary vasculature of the rat. At high concentrations (greater than those found in normal therapeutic dosing) D-nor-pseudoephedrine contracted the aorta. In contrast, it produced vasodilation on pre-contracted aorta independently of the vasoconstrictor employed or the presence of vascular endothelium.