Some beta blockers ( e . g ., labetalol and carvedilol ) exhibit mixed antagonism of both ?-and ? 1-adrenergic receptors, which provides additional arteriolar vasodilating action.
12.
However, it is extremely likely that the major force driving flow in this artery is the markedly different arterial pressures in the pulmonary and systemic circulations due to the different arteriolar resistances.
13.
Some sympathetic stimulation of arterioles in skeletal muscle is mediated by epinephrine acting on ?-adrenergic receptors of arteriolar smooth muscle, which would be mediated by cAMP pathways, as discussed above.
14.
In addition, Skagen et al . demonstrated that a patient with Dercum s disease lacked the vasoconstrictor response to arm and leg lowering, which indicated that the sympathicusmediated local veno-arteriolar reflex was absent.
15.
"' Cerebral consequences of hypertension : "'treating high blood pressure prevents only arteriolar strokes . ( . ) This research led to the understanding that the effects of therapies, designed to reduce hypertension, on blood pressure need to be distinguished from other effects on atherosclerosis.
16.
Other vascular agents such as nitric oxide ( NO ), n-nitro-l-arginine methyl ester ( L-Name ), nitroglycerin, NO + phosphodiesterase inhibitors ( i . e . Sildenafil ), and endothelin receptor antagonists have demonstrated no effect and in some cases worsening of hemorrhage due to the protective effects at the arteriolar level of the pulmonary vasculature.
