Investigation of the Effects of Leptin Treatment Towards AlphaAdrenergic Receptor Expression in Mouse Aortic, Renal, and Mesenteric Arteries and Adrenal Glands.

Abstract

Body weight gain and obesity lead to an elevation in blood pressure (BP) also called hypertension when the level of blood pressure reaches 140 and 90 mmHg for the systolic and diastolic BP respectively. Previous work from this lab demonstrated that the adipocyte-derived hormone leptin, secreted in important amounts in obesity, reduces the ability of the aortic artery to contract in response to adrenergic stimulation, likely mediated by a decreased expression of the aorta alpha-adrenergic receptors. However, it is not known whether leptin decreases the expression of alpha-adrenergic receptors in other arteries such as the mesenteric and renal, as well as the adrenal glands that play a key role in the control of BP. To determine whether leptin decreases alpha-adrenergic receptors expression in these arteries, as it does in the aorta, we infused leptin (10ug/day) by implanting subcutaneous mini-pumps in a total of 10 male C57bl/6 mice and evaluated leptin-mediated changes via alpha-adrenergic receptor expression. Real-time PCR (qPCR) conducted on the arteries revealed fold changes which were not supportive of our hypothesis that leptin- mediated sympatho-activation decreases adrenergic receptor expression.