RESUMO
Protein leakage from type I skeletal muscle cells and collagen synthesizing cells were studied during a 24-h cross-country skiing relay in eight men using serum carbonic anhydrase III (S-CA III) and serum galactosylhydroxylysyl glucosyltransferase (S-GGT) as the respective specific marker proteins. Serum aminoterminal propeptide of type III procollagen (S-Pro(III)-N-P) was used as an indicator of type III collagen synthesis and serum creatine kinase (S-CK) as a nonspecific muscular marker. S-CK, S-CA III, and S-GGT were increased immediately following the skiing relay by 870%, 640%, and 40%, respectively. No significant change was observed in the concentration of S-Pro(III)-N-P following the exercise. A high positive correlation (rs = 0.92, P less than 0.01) was found between the increase in S-CA III and S-CK, whereas no correlation was observed between these muscular markers and S-GGT. The results suggest leakage from type I skeletal muscle cells and collagen synthesizing cells as a consequence of prolonged cross-country skiing, but there seems to exist no dependence between acute responses in muscular and connective tissue cells to exercise.