Location: Obesity and Metabolism Research Unit
Title: Effects of dynamic exercise on plasma arachidonic acid epoxides and diols in human volunteers Authors
Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2011
Publication Date: August 29, 2011
Citation: Giordano, R.M., Newman, J.W., Pedersen, T.L., Ramos, M.I., Stebbins, C. 2011. Effects of dynamic exercise on plasma arachidonic acid epoxides and diols in human volunteers. American Journal of Clinical Nutrition. doi: 21, 471-479. Interpretive Summary: Exercise increases the blood flow in muscle however the biochemical signals which regulate this effect are not fully understood. One important class of metabolites that can dilate blood vessels is the epoxides formed from the 20 carbon fatty acid, arachidonic acid. In this study, we evaluated the impact of intensity and duration of exercise on circulating levels of the arachidonic acid epoxides and their degradation products, the arachidonate diols. We found that with very strenuous exercise (1.e. 80% maximal intensity), increases in arachidonic acid derived diols increased in the plasma, suggesting that this metabolic pathway does indeed have a role to play in exercise mediated vasodilation.
Technical Abstract: Metabolites of the cytochrome P450 pathway may contribute to vasodilation of the vasculature of skeletal muscle during exercise. We determined effects of exercise intensity and duration on plasma concentrations of specific metabolites in the epoxyeicosatrienoic acid family. This allowed us to determine the threshold workload, optimal workload, and time period required to produce increases in plasma concentrations of these vasoactive substances. Fourteen healthy volunteers performed maximal exercise testing on a bicycle ergometer during visit 1. On separate days subjects performed exercise testing for 20 min at 30%, 60%, and 80% of their maximal workload. The last day consisted of 40min of exercise at 60% workload. Venous blood was obtained before, during and after exercise for analysis. Compared to baseline, significant increases were observed during the 80% workload at 20 min: 14,15 DHET (0.77±0.21 vs. 0.93±0.27 pmol/ml) and at 2 min post exercise: 11,12 DHET (0.64±0.22 vs. 0.71±0.24 pmol/ml). Mean 40 min values at 60% workload were: 14,15 DHET (0.79±0.22 vs. 0.91±0.31 pmol/ml)and at 2 min post: 14,15 EET (0.12± 0.06 vs 0.21 ±0.16 pmol/ml). Results suggest that these metabolites are released during short term high intensity or long term moderate intensity exercise.