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Angiotensin II receptor blockade attenuates the deleterious effects of exercise training on post-MI ventricular remodelling in rats.
Cardiovasc Res. 2000 Apr; 46(1):66-72.CR

Abstract

OBJECTIVES

The effects of exercise training on LV remodelling following large anterior myocardial infarction (MI) remains controversial. Blockade of the renin-angiotensin system has been shown to prevent ventricular dilation and deleterious remodeling. We therefore tested, in a rat model of chronic MI, whether any potentially deleterious effects of exercise on post-MI remodelling could be ameliorated by angiotensin II receptor blockade.

METHODS

Male Wistar rats underwent coronary ligation or sham operation. Treatment with losartan (10 mg/kg/day) began 1 week post-MI and moderate treadmill exercise (25 m/min, 60 min/day, 5 days/week) was initiated 2 weeks post-MI. Systolic and diastolic pressure-volume relationships were measured in isolated, red-cell perfused, isovolumically beating hearts 8 weeks post-MI. Morphometric measurements were performed in trichrome stained cross sections of the heart. Five groups of animals were compared: sham (n=13), control MI (MI; n=11), MI plus losartan (MI-Los; n=13), MI plus exercise (MI-Ex; n=10) and MI plus exercise and losartan (MI-Ex-Los; n=12).

RESULTS

Infarct size (% of left ventricle, LV) was similar among the infarcted groups [MI=43+/-4%, MI-Los=49+/-2%, MI-Ex=45+/-1%, MI-Ex-Los=48+/-2% (NS)]. Exercise, losartan and exercise+losartan treatments all attenuated LV dilation post-MI to a similar degree. Exercise training increased LV developed pressure in both untreated and losartan treated hearts (P<0.05 vs. other MI groups). In addition, exercise resulted in additional scar thinning in untreated hearts, while no additional scar thinning was seen in post-infarct hearts receiving both losartan and exercise.

CONCLUSIONS

Following large anterior MI, losartan attenuated LV dilation and scar thinning. In untreated animals, exercise decreased dilation, but also contributed to scar thinning. Therefore, exercise concurrent with blockade of the renin-angiotensin system may provide optimal therapeutic benefit following large anterior MI.

Authors+Show Affiliations

The Cardiac Muscle Research Laboratory, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10727654

Citation

Jain, M, et al. "Angiotensin II Receptor Blockade Attenuates the Deleterious Effects of Exercise Training On post-MI Ventricular Remodelling in Rats." Cardiovascular Research, vol. 46, no. 1, 2000, pp. 66-72.
Jain M, Liao R, Ngoy S, et al. Angiotensin II receptor blockade attenuates the deleterious effects of exercise training on post-MI ventricular remodelling in rats. Cardiovasc Res. 2000;46(1):66-72.
Jain, M., Liao, R., Ngoy, S., Whittaker, P., Apstein, C. S., & Eberli, F. R. (2000). Angiotensin II receptor blockade attenuates the deleterious effects of exercise training on post-MI ventricular remodelling in rats. Cardiovascular Research, 46(1), 66-72.
Jain M, et al. Angiotensin II Receptor Blockade Attenuates the Deleterious Effects of Exercise Training On post-MI Ventricular Remodelling in Rats. Cardiovasc Res. 2000;46(1):66-72. PubMed PMID: 10727654.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Angiotensin II receptor blockade attenuates the deleterious effects of exercise training on post-MI ventricular remodelling in rats. AU - Jain,M, AU - Liao,R, AU - Ngoy,S, AU - Whittaker,P, AU - Apstein,C S, AU - Eberli,F R, PY - 2000/3/23/pubmed PY - 2000/8/12/medline PY - 2000/3/23/entrez SP - 66 EP - 72 JF - Cardiovascular research JO - Cardiovasc Res VL - 46 IS - 1 N2 - OBJECTIVES: The effects of exercise training on LV remodelling following large anterior myocardial infarction (MI) remains controversial. Blockade of the renin-angiotensin system has been shown to prevent ventricular dilation and deleterious remodeling. We therefore tested, in a rat model of chronic MI, whether any potentially deleterious effects of exercise on post-MI remodelling could be ameliorated by angiotensin II receptor blockade. METHODS: Male Wistar rats underwent coronary ligation or sham operation. Treatment with losartan (10 mg/kg/day) began 1 week post-MI and moderate treadmill exercise (25 m/min, 60 min/day, 5 days/week) was initiated 2 weeks post-MI. Systolic and diastolic pressure-volume relationships were measured in isolated, red-cell perfused, isovolumically beating hearts 8 weeks post-MI. Morphometric measurements were performed in trichrome stained cross sections of the heart. Five groups of animals were compared: sham (n=13), control MI (MI; n=11), MI plus losartan (MI-Los; n=13), MI plus exercise (MI-Ex; n=10) and MI plus exercise and losartan (MI-Ex-Los; n=12). RESULTS: Infarct size (% of left ventricle, LV) was similar among the infarcted groups [MI=43+/-4%, MI-Los=49+/-2%, MI-Ex=45+/-1%, MI-Ex-Los=48+/-2% (NS)]. Exercise, losartan and exercise+losartan treatments all attenuated LV dilation post-MI to a similar degree. Exercise training increased LV developed pressure in both untreated and losartan treated hearts (P<0.05 vs. other MI groups). In addition, exercise resulted in additional scar thinning in untreated hearts, while no additional scar thinning was seen in post-infarct hearts receiving both losartan and exercise. CONCLUSIONS: Following large anterior MI, losartan attenuated LV dilation and scar thinning. In untreated animals, exercise decreased dilation, but also contributed to scar thinning. Therefore, exercise concurrent with blockade of the renin-angiotensin system may provide optimal therapeutic benefit following large anterior MI. SN - 0008-6363 UR - https://www.unboundmedicine.com/medline/citation/10727654/Angiotensin_II_receptor_blockade_attenuates_the_deleterious_effects_of_exercise_training_on_post_MI_ventricular_remodelling_in_rats_ L2 - https://academic.oup.com/cardiovascres/article-lookup/doi/10.1016/s0008-6363(99)00429-0 DB - PRIME DP - Unbound Medicine ER -