The effect of prenatal mild unpredictable stress on the expression of monoaminoxidase А, beta 1 and 2 adrenergic receptors in the heart of adult female rat

Abstract

Introduction: Prenatal stress exposure may increase the risk of developing cardiovascular disorders later in life. Cardiotoxic effects of catecholamines are mediated via prolonged adrenergic receptors stimulation and increased oxidative stress levels upon catecholamine degradation by monoamine oxidase A (MAO-A). The aim of this study was to examine long-term effects of prenatal stress on adrenergic receptors β1 (β1AR), β2 (β2AR) and MAO-A gene expression in the heart of adult female rats. Methods: Pregnant Wistar rats were exposed to chronic unpredictable mild stress during the third week of gestation. Adult female offspring were sacrificed by decapitation and RNA was isolated from left ventricular apex and base. Real-time PCR was used to measure β1AR, β2AR and MAO-A gene expression in collected ventricular tissue samples. Results: Our results show that β1AR gene expression was higher than β2AR in both left ventricular regions in female offspring of unstressed mothers. In prenatally stressed females, regional difference in beta adrenergic receptors gene expression was lost in the left ventricular apex but not in the base. We showed that in control female offspring, MAO-A gene expression was higher in the left ventricular base compared to the apex. However, in prenatally stressed females, MAO-A gene expression was not significantly different in the examined regions. Conclusion: Our results suggest that prenatal stress modulates beta adrenergic receptors and MAO-A gene expression in the left ventricle in female offspring. Whether these changes are gender specific and whether they predispose to development of cardiovascular diseases during a lifespan, will be a subject of future experiments.