Effect Of Pravastatin On The Left Ventricular Mass Of Rabbit With Insulin Resistance

Objective :To investigate the effect of pravastatin on the left ventricular mass of rabbit with insulin resistance(RIR),which were fed with high-sucrose chow ,and its possible mechanisms.Methods: Male New Zealand white rabbits were fed either:(1) normal rabbit chow for 12 weeks;(2) high-sucrose diet for 12 weeks ;or (3) high-sucrose diet for 12 weeks supplemented by pravastatin(5mg.kg-1.d-1) for the last 4 weeks. In the beginning,8th week and at the end of the experiment , blood pressure (BP), serum concentrations of insulin,glucose and lipids were examined in all rabbits; and index of left ventricular mass (LVMI), index of cardiocyte apoptosis, concentrations of endothelin (ET) and angiotensin II (AngII) in myocardial tissue and morphological changes were investigated as well . Result: (1) compared with control group , BP,concentrations of serum insulin,lipids and of ET and AngII in myocardial tissue , index of cardiocyte apoptosis were much higher in high-sucrose group (p<0.01);except for AngII ,the other of above parameters were markedly ameliorated in pravastatin group (p<0.01); (2) Myocardial cellular hypertrophy and interstitial collagenous fibers were found more in high-sucrose group,but less in pravastatin group by optical microscope; (3) LVMI were significantly correlated with BP,serum insulin and AngII , ET in myocardial tissue positively and with ISI inversely. conclusion :(1) High-sucrose diet induced insulin resistance and left ventricular hypertrophy in New Zealand white rabbits ; (2) pravastatin can ameliorate myocardial hypertrophy in RIR ; mechanisms in pravastatin reducing left ventricular mass in RIR may be resulted from improving insulin resistance, reducing BP and concentrations of ET but not AngII in ventricular myocardium;(3) pravastatin can reduce cardiocyte apoptosis in RIR,which maybe can prevent cardiac hypertrophy into heart failure.