Journal article
Roles of nitric oxide and prostaglandins in the hyperemic response to a maximal metabolic stimulus: redundancy prevails
European journal of applied physiology, Vol.113(6), pp.1449-1456
06/2013
DOI: 10.1007/s00421-012-2570-y
PMID: 23250568
Abstract
Vasodilatory mechanisms controlling post-exercise or post-ischemic hyperemia are thought to be under redundant control and remain incompletely understood. A maximal metabolic stimulus evoked by ischemic exercise (IE) might limit redundancy by full activation of multiple pathways. We tested whether nitric oxide (NO) and/or prostaglandins contribute to the hyperemic response to IE. 17 subjects were randomized into two groups and performed three trials of IE during control (saline), N
G-monomethyl-l-arginine (l-NMMA; NOS inhibition) (protocol 1) or ketorolac (cyclooxygenase inhibition) infusion (protocol 2), and combined l-NMMA/ketorolac infusion via a brachial arterial catheter. Forearm blood flow (FBF) was measured with venous occlusion plethysmography following IE trials consisting of 5 min of ischemia and simultaneous rhythmic handgrip exercise (final 2 min). Peak and total (area under the curve) FBF and blood pressure (MAP) were measured for 3 min after each trial. Forearm vascular conductance (FVC) was calculated as FBF/MAP. Change (Δ) in peak FBF and FVC from baseline differed only between peak FBF for the saline and l-NMMA + ketorolac trials in protocol 1. Peak ΔFBF was 26.8 ± 2.5, 30.0 ± 2.8, and 33.9 ± 3.6 ml 100 ml−1 min−1 for saline, l-NMMA, and l-NMMA + ketorolac trials (P = 0.04). For protocol 1 (n = 8), total ΔFVC was 59.6 ± 4.3, 57.8 ± 6.0, and 59.9 ± 5.6 ml 100 ml−1 100 mmHg−1 for saline, l-NMMA, and l-NMMA + ketorolac trials, (P = 0.82). For protocol 2 (n = 9), total ΔFVC was 54.2 ± 5.0, 56.9 ± 4.5, and 56.5 ± 5.3 ml 100 ml−1 100 mmHg−1 for saline, ketorolac, and ketorolac + l-NMMA trials, (P = 0.69). These results suggest that NO and PGs are not obligatory for the hyperemic response to IE, and other vasodilator mechanisms predominate.
Details
- Title: Subtitle
- Roles of nitric oxide and prostaglandins in the hyperemic response to a maximal metabolic stimulus: redundancy prevails
- Creators
- Marcos Lopez - Department of Anesthesiology Vanderbilt University School of Medicine 1161 21st Avenue Nashville TN 37232 USABruno Silva - Laboratory of Exercise Sciences Fluminense Federal University Niterói Rio de Janeiro BrazilMichael Joyner - Department of Anesthesiology Mayo Clinic Rochester MN 55905 USADarren Casey - Department of Anesthesiology Mayo Clinic Rochester MN 55905 USA
- Resource Type
- Journal article
- Publication Details
- European journal of applied physiology, Vol.113(6), pp.1449-1456
- Publisher
- Springer-Verlag
- DOI
- 10.1007/s00421-012-2570-y
- PMID
- 23250568
- ISSN
- 1439-6319
- eISSN
- 1439-6327
- Language
- English
- Date published
- 06/2013
- Academic Unit
- Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984083278902771
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