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The effect of short‐term exercise training and nitric oxide on the adaptation of femoral vascular conductance at the onset of contraction
Author(s) -
Just Timothy,
Jendzjowsky Nicholas G.,
DeLorey Darren S.
Publication year - 2013
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.27.1_supplement.1136.6
Subject(s) - femoral artery , medicine , contraction (grammar) , nitric oxide , cardiology , endocrinology
We tested the hypothesis that short‐term mild‐ (M) and heavy‐intensity (H) exercise training (ET) would speed the adaptation of femoral vascular conductance (FVC) at the onset of contraction by a nitric oxide (NO) dependent mechanism. Sprague‐Dawley rats (n=18) were randomized to sedentary (S), M (20m/min5% grade) or H (40m/min5% grade) ET groups and trained 5d/wkfor 4 wks with equal ET volume. Rats were anesthetised and instrumented for measurement of arterial blood pressure and femoral artery blood flow. FVC was calculated. The triceps surae muscle group was stimulated to contract at 30% and 60% of maximal contractile force (MCF) before and after NO synthase blockade (L‐NAME, 5mg/kg IV). FVC data were fit with a mono‐exponential model. The time constant (τ) for FVC was not different (p>;0.05) between groups at 30% (S = 18 ± 13s; M = 15 ± 5s; H = 13 ± 14s) or 60% MCF (S = 24 ± 17s; M = 16 ± 4s; H = 19 ± 4s). L‐NAME increased (p<0.05) τ in all groups at 30% MCF (S = 25 ± 12s; M = 21 ± 6s; H = 27 ± 13s), but did not alter (p>;0.05) τ at 60% MCF (S = 25 ± 9s; M = 22 ± 9s; H = 20 ± 3s). The primary findings from this study were that: 1) short‐term ET did not alter the adaptation of FVC at the onset of contraction; and 2) regardless of training status, NO contributed to the regulation of FVC kinetics at the onset of moderate‐intensity contraction (30% MCF), whereas NO was not required for vasodilation at the onset of heavy‐intensity contraction (60% MCF). NSERC, Canada.