Stress in pregnancy: a new Wistar rat model for human preeclampsia.

Abstract

Our study evaluated the effects of chronic and/or acute stress on pregnant and nonpregnant female rats. The rats were exposed to the sonic stimulus associated with overpopulation between days 7 and 14 of pregnancy. The rats were immobilized 2 days before the vascular reactivity experiments. In 14-day pregnant rats, chronic stress led to lower weight, increased adrenal weight, lower endothelium-derived relaxing factor release, and lower fetal weight. In 20-day pregnant rats, chronic stress caused decreased weight gain, higher blood pressure, increased vasomotility and proteinuria, lower endothelium-derived relaxing factor release, and lower fetal weight. In the 20-day pregnant group, the higher adrenal weight resulted in higher blood pressure, lower vascular relaxation, and lower average fetal weight. A greater number of fetuses had higher adrenal weight, higher blood pressure, and lower vascular relaxation. The alterations found in the rats were similar to those that occur in human preeclampsia. Therefore, we propose a new animal model for human preeclampsia.