Carbonic anhydrase III and collagen markers in serum following cross-country skiing.

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.

Evidence of impaired left ventricular performance after an uninterrupted competitive 24 hour run.

The effect of extremely exhaustive exercise on left ventricular performance was studied echocardiographically in 13 experienced male ultramarathon runners who took part in a competitive 24 hr run, completing distances of 114 to 227 km. Although the left ventricular end-diastolic dimension (EDD) was reduced by 7% (54 +/- 5 to 50 +/- 7 mm; p less than .005), the end-systolic dimension (ESD) increased slightly (33 +/- 5 to 34 +/- 6 mm; NS). As a consequence, the stroke dimension (21 +/- 2 to 16 +/- 2 mm; p less than .005) and fractional shortening (38 +/- 5% to 32 +/- 5%; p less than .005) declined by 24% and 16%, respectively. The reduction in fractional shortening was related to delta ESD (r = -.66; p less than .05) but not to delta EDD (r = .22; NS). In spite of reduced afterload, the mean velocity of circumferential fiber shortening also decreased by an average of 9% (p less than .01) in proportion to the distance completed (r = -.69; p less than .01). The systolic blood pressure/ESD ratio was 21% lower after the race (4.2 +/- 0.9 to 3.3 +/- 0.6; p less than .005). Body weight loss was not related to any alterations in left ventricular dimensions or ejection phase indexes. The stroke dimension and ejection phase indexes continued to decline within the last 6 hr of the race but returned to the prerace level 2 to 3 days after the race. Total serum creatine kinase peaked at 3917 to 64740 U/liter (mean 27427) and its MB percentage peaked at 2% to 6%.(ABSTRACT TRUNCATED AT 250 WORDS)