title: The influence of acute resistance exercise on cyclooxygenase-1 and -2 activity and protein levels in human skeletal muscle.
abstract: This study evaluated the activity and content of cyclooxygenase (COX)-1 and -2 in response to acute resistance exercise (RE) in human skeletal muscle. Previous work suggests that COX-1, but not COX-2, is the primary COX isoform elevated with resistance exercise in human skeletal muscle. COX activity, however, has not been assessed after resistance exercise in humans. It was hypothesized that RE would increase COX-1 but not COX-2 activity. Muscle biopsies were taken from the vastus lateralis of nine young men (25 ± 1 yr) at baseline (preexercise), 4, and 24 h after a single bout of knee extensor RE (three sets of 10 repetitions at 70% of maximum). Tissue lysate was assayed for COX-1 and COX-2 activity. COX-1 and COX-2 protein levels were measured via Western blot analysis. COX-1 activity increased at 4 h (P < 0.05) compared with preexercise, but returned to baseline at 24 h (PRE: 60 ± 10, 4 h: 106 ± 22, 24 h: 72 ± 8 nmol PGH2·g total protein(-1)·min(-1)). COX-2 activity was elevated at 4 and 24 h after RE (P < 0.05, PRE: 51 ± 7, 4 h: 100 ± 19, 24 h: 98 ± 14 nmol PGH2·g total protein(-1)·min(-1)). The protein level of COX-1 was not altered (P > 0.05) with acute RE. In contrast, COX-2 protein levels were nearly 3-fold greater (P > 0.05) at 4 h and 5-fold greater (P = 0.06) at 24 h, compared with preexercise. In conclusion, COX-1 activity increases transiently with exercise independent of COX-1 protein levels. In contrast, both COX-2 activity and protein levels were elevated with exercise, and this elevation persisted to at least 24 h after RE.
authors: Department of Physiology, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA. ccarro@midwestern.edu
authors: Chad C
authors: CC
authors: Carroll
authors: Devin T
authors: DT
authors: O'Connor
authors: Robert
authors: R
authors: Steinmeyer
authors: Jonathon D
authors: JD
authors: Del Mundo
authors: David R
authors: DR
authors: McMullan
authors: Jamie A
authors: JA
authors: Whitt
authors: Jahir E
authors: JE
authors: Ramos
authors: Rayna J
authors: RJ
authors: Gonzales
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001706:Biopsy; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D020033:Protein Isoforms / Q000378:metabolism; D055070:Resistance Training; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology
chemical_list: D009124:Muscle Proteins; D020033:Protein Isoforms; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2
keywords: cyclooxygenase; exercise; human; prostaglandins; skeletal muscle