(715.12) The function of β3-adrenergic receptors in resistance-sized arteries

Poster Board Number: E89

Young Choi (Western University of Health Sciences), Angela Reinert (Western University of Health Sciences), Simon Bulley (Western University of Health Sciences)

Beta-adrenergic receptors, including the β1, β2, and β3-adrenergic receptors, are a component of the adrenergic nervous system, with significant expression identified in cardiac, airway smooth muscle, and adipose tissue, respectively. An elevated stimulation of the beta-adrenergic system has been linked to a variety of cardiovascular complications, including hypertension, heart failure, and cardiac myocyte injury. Upregulation of the β3-adrenergic receptor is observed in patients with heart failure, and it has been proposed that β3-adrenergic receptor agonists may potentially be utilized therapeutically to treat the disease. However, little is understood about the function of β3-adrenergic receptors in systemic resistance-sized arteries that regulate blood pressure, and whether their expression is altered in cardiovascular diseases, such as hypertension. Simple Western indicates that β3-adrenergic receptor expression is elevated in resistance-sized mesenteric and hindlimb arteries isolated from hypertensive C57BL/6J mice, compared to controls. Immunofluorescence of en face mesenteric artery segments reveals expression of β3-adrenergic receptors in both vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). The β3-adrenergic receptor agonists mirabegron and L-755,507 cause vasodilation in cannulated 2nd- and 3rd-order mesenteric artery segments after they have developed myogenic tone at physiological pressure (80 mmHg). These data suggest that β3-adrenergic receptors regulate arterial tone in systemic resistance-sized arteries and receptor activation may attenuate elevated vasoconstriction observed in hypertension.