P353Recreational physical exercise decreases angina susceptibility and induces cardiovascular protective shifts in nitric oxide synthase, heme oxygenase and matrix metalloproteinase regulation in rats

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Abstract

Introduction

Physicalinactivity, i.e. sedentary life style increases circulatory disease risk. Carbonmonoxide and nitric oxide produced by the heme oxygenase (HO) and by the constitutivenitric oxide synthase (cNOS) protect circulation. In contrast, the enhancedlevel of the matrix metalloproteinase (MMP) augments cardiovascular risks.

Purpose

We examined the actions of recreational physicalexercise on the expression of these enzyme systems in conjunction withcardiovascular protection.

Methods

MaleWistar rats were placed into cages installed with running wheels allowing themthe self administration of physical exercise over 6 weeks. We studied 1./ theactivity and expression of HO in the aorta and heart left ventricle (LV); and 2./the activity and expression cNOS in the aorta and LV; and 3./ the plasma levelof MMP-2; and 4./ the angina susceptibility of the heart (assessed by lead II. surfaceECG following adrenaline plus phentolamine challenge).

Results

We found that physical exercise 1./increased LV and aortic HO activity (from 0.83 ± 0.21 to 5.35 ± 0.36 and from0.73 ± 0.15 to 1.60 ± 1.13 nmol bilirubin/h/mg protein, respectively; n=12-15;p < 0.001) and LV HO-1 isoenzyme expression (from 106.3 ± 3.132 to164.0 ± 16.479%; n=6-7; p < 0.05) and 2./ increased LV and aortic cNOS activity (from16.32 ± 3.71 to 59.11 ± 7.94 and from 105.38 ± 55.72 to 181.78 ± 30.29 pmol/min/mgprotein, respectively; n=9-15; p < 0.001) and LV endothelial NOS isoenzyme expression(from 109.15 ± 5.247 to 163.1 ± 10.67%; n=3; p < 0.05); and 3./ decreased MMP-2plasma level (64 KDa; from 1002.71 ± 37.50 to 679.73 ± 34.35 intensity x mm2;n=12-13; p < 0.001); and 4./ decreased heart ischaemia susceptibility (STsegment depression: from -0.14 ± 0.018 to -0.019 ± 0.019 mV; n=11; p < 0.001).

Conclusion

Recreationalphysical exercise protects the heart against angina, which might be associatedwith the up-regulation of the HO and NOS enzyme system, and the down-regulationof MMP-2 activation.

Grant supports

SROP 4.2.1./B-09-1/KNOV-210-0005; SROP4.2.2.-08/1-2008-0006; Bolyai Scholarship(Aniko Posa).

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