Effects of lacidipine on expression of GRP78 and CHOP in vascular smooth muscle cells of rats in high temperature and humidity stress

Objective:To study the effects of Lacidipine on the expression of GRP78 and CHOP in the vascular smooth muscle cells of the high temperature and humidity stress rats.Methods:Sixty Sprague-Dawley(SD) rats were divided randomly into three groups:control group(n=20),high temperature and humidity group(n=20) and Lacidipine group(n=20).And each group included four subgroups:2w,4w,6w,8w,and each subgroup had 5 rats.Mean arterial blood pressure(MAP) was measured by carotid artery intubation.The ex-pression of GRP78 and CHOP in the vascular smooth muscle cells was detected by immunohistochemistry.Results:①Mean arterial blood pressure(MAP) of 4w、6w、8w subgroups in the high temperature and humidity group increased significantly compared with that of the according control group and the according Lacidipine group(P0.05).And it increased progressively during the experiment.②Compared with that of the according control group,the expression of GRP78 in the subgroups of 4w,6w,8w in the high temperature and humidity group increased significantly(P0.05).And OD of the 6w subgroup in the model group was the highest.③The expression of CHOP in the subgroups of 6w,8w in the high temperature and humidity group increased significantly(P0.05) compared with that of the according control group and the according Lacidipine group,and that of the 8w subgroup in the temperature and high humidity group was the highest.Conclusions:ERS is induced in the vascular smooth muscle cells of high temperature and humidity stress rats,which leads to the expression of GRP78 and CHOP increased in mismatch.This means that the high temperature and humidity stress may cause vascular smooth muscle cell damage.Lacidipine which can weaken endoplasmic reticulum stress,has a protective effect on vascular smooth muscle cells.