Expression of intercellular adhesion molecule-1 in the development of hypertensive left ventricular hypertrophy and inhibitory effect of tanshinone Ⅱ A

Chengye ZHAN; Xiuliang TAO; Cheng TIAN; Wei XIONG; Zhi ZHENG

ABSTRACT

BACKGROUND:

As a reliable marker of inflammation, intercellular adhesion molecule-1 (ICAM-1) plays an important role in atherogenesis. Recently, it is assumed in researches of recent years that chronic inflammation mediated by ICAM-1 is involved in hypertensive left ventricular hypertrophy probably, but there are still some objections reported. Tanshinone ⅡA is a kind of liposoluble extract from danshen(Radix Salviae Mitiorrhizae) . It is verified in animal experiment that it can inhibit hypertensive left ventricular hypertrophy.

OBJECTIVE:

To investigate the relationship between ICAM-1 and hypertensive left ventricular hypertrophy and the effect of tanshinone ⅡA on expression of ICAM-1.

DESIGN:

A randomized controlled observation was designed.

SETTING:

Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology.MATERIALS The experiment was performed in the Laboratory of Emergency Department of Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from October 2002 to January 2004. Ten male WKY rats(10 WKY rats) of 12-week-old and 20 rats with spontaneous hypertension(20 SHR rats) were employed and divided into the control group(10 WKY rats), hypertension group(10 SHR rats) and tanshinone ⅡA group(10 SHR rats).injected from caudal vein for treatment and distilled water at the same dose was injected in the other two groups. Twelve weeks later, the rats were sacrificed and myocardium was collected for specimen preparation. Haematoxylin and eosin(HE) staining, VG staining, immunocytochemical staining and myocardial ED1 labeling were applied to determine myocardial macrophage infiltration degree. The reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay(ELISA) were used to determine the expressions of ICAM-1 mRNA and protein.MAIN OUTCOME

MEASURES:

Degree of macrophages infiltration and the expressions of ICAM-1 mRNA and protein in myocardium in each group.

RESULTS:

Twelve SHR and 10 WKY rats were employed in the experiment pared with the control group, ICAM-1 mRNA and protein expressions in hypertrophic myocardium were increased significantly in hypertension group (0.176±0.087,0.537±0.195;0.104±0.011,0.173±0.027, P ＜0.01or P ＜ 0.05) . Infiltration of macrophage was significant(0. 62 ±0.07,non Ⅱ A group, the expressions of ICAM-1 mRNA and protein were decreased significantly(0. 537 ±0. 195, 0.291 ±0. 106; 0. 173 ±0.027, 0. 125± 0. 014, P ＜ 0.01 or P ＜ 0. 05); the amount of macrophages infiltration was decreased(1.85 ±0. 23, 1.16 ±0. 17, P ＜ 0.05) and the degree of cardiomyocytic hypertrophy and interstitial fibrosis was remarkably relieved.

CONCLUSION:

Excessive expression of myocardial ICAM-1 and its mediated inflammatory cellular infiltration plays an important role in hypertensive left ventricular hypertrophy. The inhibition of tanshinone ⅡA on left ventricular hypertrophy may be contributed to decreased expression of ICAM-1 and alleviated inflammatory cellular infiltration in myocardium.