Impacts of Cold-Stress Stimulation On Mice Pregnancy

Animals exposed to cold stress develop hypertension; however, the effects of cold-induced hypertension on pregnancy remain unclear. We therefore, aimed to investigate the impacts of cold-stress stimulation on mice pregnancy.

Four groups of mice were used in the study: non-pregnant control group (NN), non-pregnant cold-stress group (NC), pregnant control group (PN) and pregnant cold-stress group (PC). control groups were kept at 25℃, and the cold-stress groups were kept in a room for cold-stress stimulation (4 ± 2℃) for 4 hours (then back to 25℃) every day from the 1st to the 18th day.

The blood pressure of the PC was the highest among the four groups, and the hypertensive percentage of the PC was significantly increased. However, plasma angiotensinⅡ levels of the PC were the lowest. The weights of the foetus and placenta in the PC were significantly decreased compared to the PN. More apparent changes in kidneys and placenta were observed in the PC compared to the PN. The blood pressure of pregnant mice showed no difference between the PN and PC groups 50 days after delivery.

Intermittent cold-stress stimulation had significantly adverse effects on the pregnant mice, leading to maternal hypertension, renal and placental lesions, body weight and placenta reduction in offspring. The study results may offer a non-invasive method to establish an animal model of hypertensive disorders in pregnancy. Cold-stress stimulation may be one of the inducible factors of pregnancy-induced hypertension.Cold-stress stimulation may be one of the inducible factors of pregnancy-induced hypertension.