Activation of PPARγ by pioglitazone does not attenuate left ventricular hypertrophy following aortic banding in rats
- First Online:
- 134 Downloads
Sustained left ventricular hypertrophy (LVH) accelerates cardiac dysfunction and heart failure. Previous reports have suggested that activation of the peroxisome proliferator-activated receptor γ (PPARγ)-dependent pathway is involved in development of cardiac hypertrophy. Thiazolidinediones (TZDs) such as pioglitazone activate PPARγ and are clinically used as antidiabetics. Given inconsistent reports regarding effects of TZDs on LVH, we examined in the present study the influence of pioglitazone on LVH in a rat model of aortic banding. Aortic banding was induced in rats by clipping the ascending aorta. Animals received pioglitazone (3 mg/kg/day) or placebo. Echocardiographic, hemodynamic, histological, and biochemical measurements were performed after 2 and 4 weeks. Pressure gradient was comparable between pioglitazone- and placebo-treated animals after 2 and 4 weeks. Left ventricular function was not different between the groups. In sham as well as in banded animals, LV/body weight ratio was increased in pioglitazone- as compared to placebo-treated animals after 2 and 4 weeks. Furthermore, an increase in myocyte size and atrial natriuretic factor was observed in pioglitazone- compared to placebo-treated animals 4 weeks after aortic banding as well. The results of this study demonstrate that activation of PPARγ via pioglitazone does not protect the myocardium from pressure overload-induced LVH in a rat model of aortic banding. The findings rather indicate a pro-hypertrophic effect of pioglitazone treatment after aortic banding.
KeywordsPioglitazone PPARγ Left ventricular hypertrophy Cardiac remodeling Aortic banding
- Sakai S, Miyauchi T, Irukayama-Tomobe Y, Ogata T, Goto K, Yamaguchi I (2002) Peroxisome proliferator-activated receptor-gamma activators inhibit endothelin-1-related cardiac hypertrophy in rats. Clin Sci (Lond) 103(Suppl 48):16S–20SGoogle Scholar