Verapamil decreases calpain-1 and matrix metalloproteinase-2 activities and improves hypertension-induced hypertrophic cardiac remodeling in rats.

AIMS: Increased activity of calpain-1 and matrix metalloproteinase (MMP)-2 was observed in different models of arterial hypertension and contribute to thicken the left ventricle (LV) walls and to hypertrophy cardiac myocytes. MMP-2 activity may be regulated by calpain-1 via bioactive molecules activation such as transforming growth factor (TGF)-β in cardiovascular diseases. This study analyzed whether calpain-1 causes cardiac hypertrophy and dysfunction by modulating the expression and activity of MMP-2 in renovascular hypertension.

MAIN

METHODS

Male Wistar rats were submitted to two kidneys, one clip (2K1C) model of hypertension or sham surgery and were treated with verapamil (VRP, 8 mg/kg/bid) by gavage from the second to tenth week post-surgery. Systolic blood pressure (SBP) was weekly assessed by tail-cuff plethysmography and morphological and functional parameters of LV were analyzed by echocardiography. MMP-2 activity was analyzed by in situ and gelatin zymography, while calpain-1 activity by caseinolytic assay. MMP-2, calpain-1, TGF-β and MMP-14/TIMP-2 levels were identified in the LV by western blots. Fluorescence assays were performed to evaluate oxidative stress, MMP-2 and calpain-1 levels.

KEY FINDINGS: SBP increased in 2K1C rats and was unaltered by VRP. However, VRP notably ameliorated hypertension-induced increase in LV thickness. VRP decreased hypertension-induced enhances in calpain-1 and MMP-2 activities, oxidative stress and mature TGF-β levels. Treatment with VRP also decreased the accentuated MMP-14/TIMP-2 levels in 2K1C.

SIGNIFICANCE: Treatment with VRP decreases calpain-1 and MMP-2 activities and also reduces TGF-β and MMP-14/TIMP-2 levels in the LV of hypertensive rats, thus contributing to ameliorate cardiac hypertrophy.