Influences of Ca~(2+) antagonist on the mRNA levels of L-type Ca_(2+) channel and Na~+ -Ca~(2+) exchanger in the atria of hypertensive rats / 中国病理生理杂志

ABSTRACT

AIM: To investigate the mRNA changes of L-type Ca~(2+) channel ?_(1C) subunit (CaL-?_(1C)) and Na~+-Ca~(2+) exchanger (NCX) in the atria of renovascular hypertensive rats. METHODS: Two-kidney one-clip Goldblatt hypertensive Sprague-Dawley rats were divided into three groups 1 week after operation, HD group was treated with 250 mg/d diltiazem, LD group was treated with 50 mg/d diltiazem, control group (C group) was treated with vehicle. After 4 weeks treatment, semiquantitative RT-PCR was used to estimate the mRNA changes of CaL-?_(1C) and NCX, and GAPDH was used as internal control. RESULTS: Systolic blood pressure in LD group was comparable with C group, and that in HD group was decreased to normal level after diltiazem treatment. In C group, CaL-?_(1C) mRNA level were 2.5, 2.4 and 2.1 times of S, HD and LD group, and NCX mRNA level were 1.9, 1.6 and 2.1 times of S, HD and LD group. There were no significant difference in the mRNA level of CaL-?_(1C) and NCX among S, HD and LD group. CONCLUSION: The mRNA levels of CaL-?_(1C) and NCX are upregulated in the atria of hypertensive rats. Ca~(2+) antagonist inhibits their upregulation independent of blood pressure.