Epidermal growth factor receptor involvement in cardiovascular remodeling in renovascular hypertensive rats / 中国药理学通报

ABSTRACT

Aim To determine the possibilities and mechanisms of EGFR, a receptor protein tyrosine kinase associated with many important cellular processes re-sponsible for cardiovascular remodeling in renovascular hypertensive rats. Methods 2K1C hypertensive rats were used in the present study. Blood pressure was measured with the tail-cuff method. LVMI and his-topathological changes in the cardiovascular system were analysed. EGFR expressions of aorta and myocar-dium as well as phosphorylation levels of ERK in hy-pertensive rats were detected by immunohistochemistry and Western blot analysis, respectively. Results Sys-tolic blood pressure was markedly increased 2 weeks after 2K1C surgery. Cardiovascular remodeling induced by hypertension was confirmed by elevated LVMI, pro-liferation of collagen fibers in myocardial interstitium, histopathological changes in cardiovascular system and increased IMT of thoracic aorta 6 weeks after 2 K1 C surgery. Compared with sham rats, EGFR expression in the ventricular myocardium of 2 K1 C rats was signifi-cantly increased at 6 weeks ( P<0. 05 ) , and the EG-FR/GAPDH ratio was higher in 2 K1 C rats with higher systolic blood pressure ( P < 0. 05 ) . Phosphorylation level of ERK 1/2 was upregulated correspondingly in 2 K1 C rats ( P <0. 01 ) . Increased EGFR expression was also found in aortas of 2K1C rats, particularly in tunica intima and media. Conclusion EGFR and its down-stream kinases ERK 1/2 are involved in cardio-vascular remodeling in association with the severity of hypertension in renovascular hypertensive rats.