MgSO4 prevents left ventricular dysfunction in an animal model of preeclampsia

Objective We hypothesized that cardiac function would be reduced in a pregnant rat model of preeclampsia induced by L-NAME, a NOS inhibitor, and be reversed with magnesium sulfate prophylaxis. Study design Female Sprague-Dawley rats were bred in-house. On gestational day 17, rats were anesthetized and osmotic minipumps were implanted to continuously deliver saline, L-NAME, or L-NAME and MgSO4. On gestational day 21, hearts were isolated and perfused in the working mode using Krebs Henseleit buffer. Results Pregnant rats treated with L-NAME displayed significant hypertension compared to the saline-treated controls (P< 0.05). Moreover, cardiac output and cardiac work were significantly reduced in the L-NAME-treated rats compared to controls (P< 0.05). In the L-NAME-treated rats given MgSO4, cardiac function remained normal. Conclusion Cardiac function is depressed in an animal model of preeclampsia induced by L-NAME infusion. MgSO4 prevented the reduction in cardiac function and is clearly beneficial in preserving normal heart function in preeclampsia.