AJP-Heart and Circulatory Physiology Podcast

How does in utero glucocorticoid administration impact autonomic control of the heart in adult offspring in a sex-dependent manner? In this episode, Associate Editor Dr. Crystal Ripplinger (University of California – Davis) interviews authors Dr. Taben Hale and Lakshmi Madhavpeddi (University of Arizona) along with expert Dr. Glen Pyle (University of Guelph) about the new work by Madhavpeddi et al. The authors administered dexamethasone to pregnant rats using a dose and timing that closely mimicked clinical application of dexamethasone administration to pregnant women at risk for preterm delivery to prevent respiratory distress in newborns. At baseline, the authors did not observe any differences between the prenatally-exposed offspring and controls. In response to an experimental stressor, however, the authors found that prenatal exposure to dexamethasone resulted in exaggerated blood pressure and heart rate only in adult female rats. Prenatally-exposed adult male rats did not exhibit any stress response changes in cardiovascular function. In addition, only the dexamethasone-exposed adult female offspring showed a reduction in the high frequency component of heart rate variability, indicating withdrawal of parasympathetic activity. What role does angiotensin II play in the altered autonomic response induced by prenatal dexamethasone exposure? Can we derive important potential clinical applications of this work related to the long-term impact on offspring from treatments administered during their mothers’ pregnancies? Listen now to find out.

L. Madhavpeddi, B. Hammond, D. L. Carbone, P. Kang, R. J Handa, T. M. Hale Impact of angiotensin II receptor antagonism on the sex-selective dysregulation of cardiovascular function induced by in utero dexamethasone exposure Am J Physiol Heart Circ Physiol, published March 17, 2022. DOI: 10.1152/ajpheart.00587.2021