Influences of hyperhomocysteine on expressions of myocardial GRP78 and CHOP and left ventricular ;hypertrophy in hypertensive rats
ZHANG Zhi-min
ZHAO Lian-you
LU Fan
ZOU Qing
LI Xue
DING Lu
WEI Cong-ying
Abstract：Objective To observe the influences of hyperhomocysteine (Hcy) on expressions of myocardial GRP78 and CHOP (relative factors to endoplasmic reticulum stress, ERS), and discuss the relationship between Hcy and left ventricular hypertrophy. Methods The rat model of hypertension was established by using abdominal aortic coarctation and after 2 w, caudal artery pressure was detected with non-invasive caudal artery piezometer and 40 hypertensive rats were randomly divided into control group and homomethionine group (Hmn group, each n=20). Control group was given normal diet and Hmn group was given diet with 2%methionine. According to feeding time after grouping, the two groups were further divided into 4-w Hmn or control subgroups and 8-w Hmn or control subgroups respectively (each n=10). The level of SBP was detected by using non-invasive caudal artery piezometer, concentreation of plasma Hcy was detected by using Hcy detector, and heart weight index (HWI) and left ventricular weight index (LVWI) were calculated after weighing body weight, heart weight and left ventricular weight. The changes of cardiomyocyte morphology were observed after HE staining, and expressions of GRP78 and CHOP were detected by using immunohistochemistry technique. Results ①Hcy level did not increased in control group and increased gradually in Hmn group, and was significantly higher in Hmn group than that in control group (P<0.01). ②The level of SBP increased in two groups with the time. The comparison between 4-w Hmn or control subgroups showed that SBP was higher in 4-w Hmn group than that in 4-w control group but the different was not statistically significant (P>0.05). The comparison between 8-w Hmn or control subgroups showed that SBP was significantly higher in 8-w Hmn group than that in 8-w control group (P<0.05). ③HWI and LVWI increased significantly in 4-w and 8-w Hmn or control subgroups, which was more significant in 4-w and 8-w Hmn subgroups (P<0.05). ④The expression of GRP78 was significantly higher in Hmn group than that in control group (P<0.05) on the 4th w, and expression of CHOP was much significantly higher in Hmn group than that in control group (P<0.05) on the 8th w. Conclusion Higher level of serum Hcy can exacerbate cardiomyocyte ERS and induce disorder of GRP78 and CHOP expressions. When CHOP expression is dominant, left ventricular hypertrophy will be exacerbated. ERS may be one of molecular biomechanisms of higher Hcy exacerbating left ventricular hypertrophy.
Keywords：HyperhomocysteineHypertensionLeft ventricular hypertrophyEndoplasmic reticulum stressats
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 223-226,228 )