Prenatal infection with Mycoplasma pulmonis in rats exaggerates the angiotensin II pressor response in adult offspring.

In this study, the impact of prenatal infection (PNI), using a naturally occurring rodent pathogen, Mycoplasma pulmonis (MP), on adult body weight and cardiovascular function was evaluated. Pregnant Sprague Dawley rats were infected with MP on gestational day 14 and gave birth naturally. Adult PNI offspring of weighed more than controls, but resting mean arterial pressure (MAP) was unchanged. Subcutaneous injection of angiotensin II (Ang II; 10 μg/kg) elicited a rise in MAP that was greater in both male and female PNI offspring compared to controls (P<0.03). The accompanying reflex bradycardia was similar to the controls, suggesting PNI induced baroreflex dysfunction. Subcutaneous nicotine administration, a potent cardiorespiratory stimulus, also elicited a transient rise in MAP that was generally greater in the PNI group, but the change in MAP from baseline was only significant in the PNI females compared to controls (P<0.03). Elevated body weight and cardiovascular reactivity in the PNI offspring was associated with an increase in the ratio of hypothalamic corticotrophin-releasing hormone receptors Type 1: Type 2 gene expression in both sexes compared to controls. These findings support previous studies demonstrating that PNI induces alterations in cardiovascular function and body weight. Yet, unlike previous studies utilizing other models of PNI (ie. endotoxin), MP PNI did not induce resting hypertension. Thus, our study provides a foundation for future studies eval...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research