Journal article
Ischemic exercise hyperemia in the human forearm: reproducibility and roles of adenosine and nitric oxide
European journal of applied physiology, Vol.112(6), pp.2065-2072
2012
DOI: 10.1007/s00421-011-2035-8
PMID: 21947452
Abstract
The roles of local metabolites in reactive and exercise hyperemia remain incompletely understood. A maximum metabolic stimulus caused by ischemic exercise (IE) could potentially fully activate all vasodilator pathways and limit potential redundancy amongst vasoactive substances. We tested the hypotheses that IE elicits a reproducible hyperemic response in the forearm and that adenosine (ADO) and nitric oxide (NO) contribute to this response. In separate protocols, forearm blood flow (FBF) was measured with venous occlusion plethysmography following IE trials consisting of 5 min of ischemia and rhythmic forearm handgrip exercise (performed during last 2 min of ischemia). In protocol 1 (n = 8), FBF was measured after three trials of IE. In protocol 2 (n = 9), subjects performed IE during control (saline), aminophylline (APH; adenosine receptor antagonist), and combined APH/N (G)-monomethyl-L-arginine (L-NMMA; NOS inhibition) infusions. In protocol 1, coefficients of variation for total (area under the curve) ΔFBF and ΔFVC (forearm vascular conductance) following IE were 10.4 ± 1.0% and 14.9 ± 1.0%, respectively. In protocol 2, peak ΔFBF was similar for saline and APH trials. Peak ΔFBF for the APH+L: -NMMA trial was greater than that of the APH trial (P = 0.03), and peak ΔFVC was marginally non-significant (P = 0.053). Total ΔFBF (54.8 ± 3.9, 55.2 ± 5.4, and 60.4 ± 4.8 ml 100 ml(-1); P = 0.43) and ΔFVC (51.4 ± 3.5, 52.1 ± 5.5, and 56.5 ± 5.0 ml 100 ml(-1) 100 mmHg(-1); P = 0.52) were similar for saline, APH, and APH+L: -NMMA, respectively. Our data suggest that (1) the hyperemic response to IE is reproducible and (2) inhibition of ADO alone or combined ADO and NO does not blunt the hyperemic response following IE.
Details
- Title: Subtitle
- Ischemic exercise hyperemia in the human forearm: reproducibility and roles of adenosine and nitric oxide
- Creators
- Marcos G LOPEZ - Department of Anesthesiology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55905, United StatesBruno M SILVA - Laboratory of Exercise Sciences. Fluminense Federal University, Niterói, Rio de Janeiro, BrazilMichael J JOYNER - Department of Anesthesiology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55905, United StatesDarren P CASEY - Department of Anesthesiology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55905, United States
- Resource Type
- Journal article
- Publication Details
- European journal of applied physiology, Vol.112(6), pp.2065-2072
- Publisher
- Springer
- DOI
- 10.1007/s00421-011-2035-8
- PMID
- 21947452
- ISSN
- 1439-6319
- eISSN
- 1439-6327
- Language
- English
- Date published
- 2012
- Academic Unit
- Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984083290102771
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