We have demonstrated that myocardial
ATP-sensitive
potassium (K(
ATP)) channels are implicated in the development of
cardiac hypertrophy in hyperlipidemic rabbits. We investigated the effect of
pravastatin on development of ventricular
hypertrophy in male normolipidemic Wistar rats with two-kidney, one-
clip (2K1C)
hypertension and whether the attenuated hypertrophic effect was via activation of K(
ATP) channels. Twenty-four hours after the left renal artery was clipped, rats were treated with one of the following
therapies for 8 wk: vehicle,
nicorandil (an agonist of K(
ATP) channels),
pravastatin,
glibenclamide (an antagonist of K(
ATP) channels),
hydralazine,
nicorandil plus
glibenclamide, or
pravastatin plus
glibenclamide. Systolic blood pressure, relative left ventricular (LV) weight, and cardiomyocyte sizes significantly increased in vehicle-treated 2K1C rats compared with those in
sham-operated rats. Treatment with either
nicorandil or
pravastatin significantly attenuated LV
hypertrophy/
body weight compared with the vehicle, which was further confirmed by downregulation of LV
atrial natriuretic peptide mRNA.
Nicorandil-induced effects were abolished by administering
glibenclamide. Similarly,
pravastatin-induced beneficial effects were reversed by the addition of
glibenclamide, implicating K(
ATP) channels as the relevant target. A dissociation between the effects of blood pressure and cardiac structure was noted because
pravastatin and
hydralazine reduced arterial pressure similarly. These results suggest a crucial role of cardiac K(
ATP) channel system in the development of ventricular
hypertrophy in the 2K1C hypertensive rats.
Pravastatin is endowed with cardiac antihypertrophic properties probably through activation of K(
ATP) channels, independent of
lipid and hemodynamic changes.