Acute Intranasal Insulin Increases MSNA in Healthy Adults

AJP-Heart and Circulatory Physiology Podcast

What is the impact of central insulin on muscle sympathetic nerve activity (MSNA) and vascular conductance in the absence of peripheral insulin delivery? Listen as Associate Editor Dr. Jason Carter (Baylor University) interviews authors Neil McMillan and Dr. Jackie Limberg (both at University of Missouri), along with expert Dr. Manda Keller-Ross (University of Minnesota), about the new Short Report by McMillan et al. To gain a better understanding of the central sympathoexcitatory effects of insulin in humans, the authors recruited two groups of young, healthy individuals. One group served as a time control and the other group received intranasal insulin administration. McMillan et al. measured MSNA from the fibular nerve, combined with continuous monitoring of blood pressure and leg blood flow, before and after insulin administration. Limberg, McMillan and co-authors found that only the individuals who received insulin exhibited an increase in efferent sympathetic nervous system activity, which was coupled with peripheral vasoconstriction and increases in arterial blood pressure. How does this research influence our mechanistic understanding of the sympathetic and hemodynamic response to insulin? Listen now to find out.

Neil J. McMillan, Dain W. Jacob, Brian Shariffi, Jennifer L. Harper, Glen E. Foster, Camila Manrique-Acevedo, Jaume Padilla, and Jacqueline K. Limberg Effect of acute intranasal insulin administration on muscle sympathetic nerve activity in healthy young adults Am J Physiol Heart Circ Physiol, published July 3, 2024. DOI: 10.1152/ajpheart.00253.2024