Effects Of Prenatal Exercise On Cardiac Morphology And Function In SHR Offspring

Abstract

Intrauterine environment during pregnancy has important effects on the cardiovascular development of the offspring, which could persist into adulthood. However, it is largely unknown whether maternal exercise during pregnancy has a beneficial effect on cardiac structure and function in the offspring of spontaneously hypertensive rats (SHR). PURPOSE: To investigate the effects of prenatal exercise on cardiac morphology and function in 3-month-old male offspring of SHR. METHODS: Pregnant SHR and Wistar-Kyoto rats (WKY) were separated into a sedentary group (p-WKY-SED, p-SHR-SED) and an exercise group (p-WKY-EX, p-SHR-EX) at random. Exercise group were subjected to swimming (60 min/day, 6 day/week, gestation day 1-19). Physical characteristics, myocardial cell morphology, myocardial collagen volume fraction (CVF%) and cardiac function of male offspring were evaluated at 3 months (3 M). RESULTS: 1) Prenatal exercise significantly decreased the diastolic blood pressure (DBP) and mean arterial pressure (MAP) in the offspring of SHR (DBP: 153.5 ± 2.12 vs. 146.7 ± 1.38 mmHg, p < 0.01; MAP: 169.3 ± 2.60 vs. 161.9 ± 3.82 mmHg, p < 0.01). 2) Prenatal exercise significantly decreased the left ventricular hypertrophy index at 3 M in the offspring of SHR (0.74 ± 0.01 vs. 0.70 ± 0.02, p < 0.05). 3) Loosely arranged cardiomyocytes and significant increase in CVF% in the pathological state of hypertension (6.13 ± 0.70 vs. 20.33 ± 1.36 p < 0.01). Prenatal exercise improved cardiomyocyte morphology and decreased CVF% in the offspring of SHR (20.33 ± 1.36 vs. 14.91 ± 0.72 p < 0.05). 4) Echocardiographic results showed that the p-SHR-SED group had a lower left ventricular ejection fraction (LVEF%) (82.33 ± 4.14 vs. 74.14 ± 1.92 p < 0.05), lower cardiac output (CO) (137 ± 6 vs. 100 ± 5 ml/min, p < 0.05) and significantly lower left ventricular short-axis contraction rate (LVFS%) (52.93 ± 1.56 vs. 42.81 ± 1.05, p < 0.01) compared to the p-WKY-SED group, while the exercise group showed no significant differences compared to their respective sedentary control groups (p > 0.05). CONCLUSION: Prenatal exercise significantly reduces DBP and MAP in 3 M male offspring of SHR and improves cardiac morphology in the pathological state, but do not significantly improve cardiac function.Supported by the National Natural Science Foundation of China 32071174.