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Effect of exercise training on skeletal muscle pressor reflexes in chronic heart failure rats
Author(s) -
Pan Yanxia,
Fahim Mohammad,
Zucker Irving H.,
Wang Wei
Publication year - 2006
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.20.5.a1196-c
Subject(s) - medicine , reflex , heart failure , skeletal muscle , stimulation , endocrinology , isometric exercise , cardiology
Nebrasaka Medical Center, Omaha, Nebraska, 68198‐5850 Exercise pressor reflex (EPR) arising from activation of group III endings in contracting skeletal muscle is predominantly mechanically sensitive and from group IV endings metabosensitive. In chronic heart failure (CHF) these reflex responses are disturbed contributing to exercise intolerance. In the present study, we tested the hypothesis that exercise training (ET) improves EPR in CHF rats. CHF induced by coronary artery ligation was confirmed by a significant fall in ejection fraction (EF). Mechanoreflex was elicited by electrical stimulation of L4/L5 spinal ventral roots and metaboreflex by intra‐arterial injection of capsaicin. Renal sympathetic nerve activity (RSNA) was increased during EPR. Mechanoreflex pressor response was enhanced and metaboreflex response was inhibited in CHF. ET restored the normal EPR in CHF rats. Muscle citrate synthase activity (CS) was decreased in CHF. ET produced a rise in CS in sham and CHF rats. An increase in CS in exercise trained rats suggests that the adaptation to ET increases oxidative capacity of skeletal muscle cells which might be partly responsible for improvement in cardiovascular function in CHF. ( Supported by NIH grant PO1 HL 62222; RO‐1 HL 077691 )