title: Serum carbonic anhydrase III, an enzyme of type I muscle fibres, and the intensity of physical exercise.
abstract: The effects of 30 min running with stepwise increasing intensity (exhaustive, energy demand approx. 50----100% of VO2max), 60 s supramaximal running (anaerobic, greater than or equal to 125% of VO2max) and 40-60 min low-intensity running (aerobic, 40-60% of VO2max) on serum concentration of muscle-derived proteins were studied in 5 male and 5 female elite orienteerers. S-Carbonic anhydrase III (S-CA III) was used as a marker of protein leakage from type I (slow oxidative) muscle fibres and S-myoglobin (S-Mb) as a non-selective (type I + II) muscular marker. The fractional increase in S-CA III (delta S-Ca III) was 0.37 +/- 0.09 (mean +/- SEM, p less than 0.001), 0.10 +/- 0.05 (N. S.) and 0.46 +/- 0.09 (p less than 0.001) 1 h after exhaustive, anaerobic and aerobic exercise, respectively. The corresponding values for delta S-Mb were 1.45 +/- 0.36 (p less than 0.001), 0.39 +/- 0.13 (p less than 0.01) and 0.67 +/- 0.18 (p less than 0.001). The value for the delta S-CA III/delta S-Mb ratio was 0.68 +/- 0.03 after the aerobic exercise, but only 0.25-0.26 (p vs. aerobic exercise less than 0.001) after the two high-intensity forms of exercise. Since type I fibres of skeletal muscle are known to be responsible for power production during low-intensity exercise, whereas fibres of both type I and type II are active at higher intensities, the delta S-CA III/delta S-Mb ratio may depend on the recruitment profile of type I vs. type I + II fibres.
authors.affiliation: Department of Sports Medicine, Deaconess Institute of Oulu, Finland.
authors.forename: T E
authors.initials: TE
authors.lastname: Takala
authors.forename: P
authors.initials: P
authors.lastname: Rahkila
authors.forename: E
authors.initials: E
authors.lastname: Hakala
authors.forename: J
authors.initials: J
authors.lastname: Vuori
authors.forename: J
authors.initials: J
authors.lastname: Puranen
authors.forename: K
authors.initials: K
authors.lastname: Väänänen
mesh_terms: D000328:Adult; D002256:Carbonic Anhydrases / Q000097:blood / Q000378:metabolism*; D003402:Creatine Kinase / Q000097:blood / Q000378:metabolism; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology; D009211:Myoglobin / Q000378:metabolism; D010101:Oxygen Consumption; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D009124:Muscle Proteins; D009211:Myoglobin; D012709:Serum Albumin; D003402:Creatine Kinase; D002256:Carbonic Anhydrases