Aim To investigate the effects of various antihypertensive drugs on
left ventricular hypertrophy and the expression of
atrial natriuretic peptide(ANP) in the left ventricle in spontaneously hypertensive rat(SHR).\ Methods After the measurement of systolic blood pressure(SBP), adult male SHRs(16 wk old) were randomly divided into 3 groups. Ratseach was given captopril(Cap,100 mg/kg·d -1 ),dihydrochlorothiazide(DCT,100 mg/kg·d -1 ),propanolol(Pro,40 mg/kg·d -1 ) for 12 weeks respectively ,sex age and number matched untreated SHR and normotensive WKY served as controls.\ Body weights and SBP were measured before decapitation.\ Left ventricle was subjected to guanidine thiocyanate phenol chloroform procedure for RNA extraction.\
Left ventricular hypertrophy(LVH) was assessed by left ventricle weight to body weight ratio(LVW/BW).\ ANP expression was deternmined by Northern Blot.\ Results Treated animals in Cap and pro groups showed a significant lowering in SBP and LVW/BW, while LVW/BW in DCT treated SHR was similar to that of WKY(3 29±0 33 vs 2 80±0 64 mg/g,P>0 05).\ The expression of ANP mRNA was supressed by the three drugs. The decreased degree of ANP was more slight in DCT group compared with cap and pro groups.\ Conclusion Accompanied by the reversion of LVH, expression of ANP was supressed with various degree by different antihypertensive drugs.\ Difference in supressive effects of various drugs on ANP expression may be thhe results of the different hemodynamics and cardiovasoactive factors in hypertension.