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Exercise is associated with an acute improvement in myocardial ischemic tolerance and skeletal muscle enkephalin release
Author(s) -
Hogrefe Christopher P,
Ludwig Paula S,
Denning Gerene M,
Barna Thomas J,
Ackermann Laynez W,
Stoll Lynn L,
Weintraub Neal L,
Dickson Eric W
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a570-c
Subject(s) - skeletal muscle , proenkephalin , cardioprotection , medicine , enkephalin , endocrinology , opioid peptide , cardiac muscle , ischemia , opioid , receptor
Exercise is associated with both increased serum opioid levels and improvements in cardiovascular health. We hypothesize that one class of opioids, the enkephalins, contributes to the acute cardioprotective effects of exercise. We further hypothesize that enkephalins are released from skeletal muscle in response to exercise, and act hormonally to evoke a cardioprotective effect. To test these hypotheses, we assessed the effect of exercise on skeletal and cardiac muscle proenkephalin (PENK) expression, as well as on myocardial ischemic tolerance. We found that exercise was profoundly cardioprotective in the rat. Additionally, exercise was associated with a change in PENK levels in skeletal and cardiac muscle, but not in intestine. Finally, hearts from exercised animals appeared to have an enhanced ischemia‐induced enkephalin release relative to control animals. These findings, coupled with our recent report that enkephalins can be absorbed from skeletal muscle and can induce a cardioprotective effect, strongly support our hypothesis that exercise‐induced enkephalin release from skeletal muscle, acting hormonally, contributes to acute cardioprotection.