Effect of Cold-Stress on Rennin-Angiotensin System in Pregnant Rats / 环境与健康杂志

ABSTRACT

Objective To determine whether repeated cold-stress stimulation could activate rennin-angiotensin system in rats and lead to a PIH-like phenomena in pregnant rats.Methods Adult Wistar female rats were randomly divided into 4 groups non-pregnant control group(NN), non-pregnant cold-stress group(NC), pregnant control group(PN) and pregnant cold-stress group(PC). Rats were kept for 4 hours in (4?2)℃(NC?PC) and in 25℃ (NN?PN) every day respectively, from the 1st day to the 19th day of pregnancy. The AngⅡlevels of plasma?uterus and placentas were determined by radioimmunoassay. The expression of angiotensin Ⅱ type 1 receptor (AT1R) and angiotensin Ⅱ type 2 receptor (AT2R) mRNA were determined in uterus and placentas of rats by RT-PCR. Results The AngⅡlevels of plasma, uterus and placentas were increased significantly in NC and PC compared with those in NN and PN. AT2R was the predominant type in the rat non-pregnant uterus. Downregulation of AT2R and upregulation of AT1R were observed during pregnancy. And at last, AT1R was the predominant type in pregnant uterus. The AngⅡ receptors in the rat placenta are predominantly AT1R. After cold-stress stimulation, the expression of AT1R mRNA in uterus and placentas of rats were higher than that of control groups(P0.05). Conclusions Repeated cold-stress stimulation could activate the renin-angiotensin system(RAS), and lead to a PIH-like phenomena in pregnant rats at last.