Inhibitory effect of exercise on elevated blood pressure and fetal growth restriction during pregnancy in Dahl salt-sensitive rats

Exercise is effective in preventing gestational hypertension, but its mechanism remains unclear. This study investigates the effects of exercise on Dahl salt-sensitive (DSS) rats, which develop elevated blood pressure and fetal growth restriction during pregnancy. DSS rats were divided into exercise and non-exercise groups, with Sprague-Dawley rats as controls. Exercise consisted of voluntary running, starting 4 weeks prior to pregnancy until the last trimester. Cardiovascular parameters, molecular characteristics of the brain and placenta, and fetal conditions were evaluated. Exercise significantly improved elevated blood pressure at early pregnancy and was associated with improved baroreceptor reflex gain. Gene expression analysis in the rostral ventrolateral medulla (RVLM) showed exercise-induced downregulation of nitric oxide synthase and upregulation of superoxide dismutase. These genetic changes suggest that exercise impacts circulatory regulation mechanisms, contributing to blood pressure improvement. In addition, placental analysis revealed a marked increase in placental growth factor expression due to exercise. In conclusion, exercise alleviates elevated blood pressure at early gestation and fetal growth restriction in DSS rats. Genetic modifications in the RVLM may play a critical role in exercise-induced cardiovascular improvements. This study highlights the potential of exercise as a therapeutic approach for managing gestational elevated blood pressure and fetal growth restriction and provides insights into its underlying mechanisms.