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IggT).Downregulation of PPAR cvis considered to be a compensatory mechanism which
will cause an alteration of energy utilization in heart thus preserving the heart function
against pressure overload (Young et al. 2001). The administration of PPAR a agonist was
able to prevent the endothelin-l induced hypertrophy in isolated myocytes and at the
same time prevent the process of cardiac remodeling and the occlurence of interstitial
fibrosis in in vivo models of hypertension (Diep et aL.2002b;Iglarz et al' 2003).
V.f. PPAR and Heart Faiture
Recently it was reported that PPAR Blõ may play an important role in the
pathogenesis of heart failure. The PPAR 0/ô mice knockouts exhibited signs of severe
cardiac dysfunction which was accompanied by a progressive myocardial lipid
accumulation and development of cardiac hypertrophy (Cheng et al. 2004)' A chronic
PPAR B/ô deficiency was shown to lead to the development of lipotoxic cardiomyopathy
which can progress in to congestive heart failure (Cheng et aL.2004). Although the heart
is found to contain high levels of PPARs and RXR receptors, until recently very little was
known on the role of PPARs in cardiac function and disease. Recent studies on the role of
PPARs in physiological and pathological process and successful usage of PPAR agonist
in the treatment of number of pathological process involving cardiovascular system
indicate that PPARs may be a significant factor in the control of cardiovascular
processes. PPARs are now been implicated to play a significant role in the pathogenesis
of heart failure and apoptosis, however, the exact mechanism of their action on
cardiovascular system, specifically heart is still unknown. A number of studies have
shown that the usage of PPAR y agonists was able to prevent and limit ischemia and
reperfusion injury in rats (Khandoudi et al. 2002; Molavi et aL.2005; Yue Tl et al. 2001).
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