Plasma @entity908 kinase responses of 18- to 30-yr-old African-American XXXX to eccentric exercise.

@entity1 @entity908 @entity925 @entity121
PURPOSE: The primary aim was to describe the response of plasma @entity908 kinase (CK) activity in a sample of African-American @entity1 after a bout of eccentric exercise. The study also described signal intensity changes detected by MR in the musculature of the right lower leg. METHODS: Subjects were 20 male volunteers of African descent (age = 24 +/- 4 [mean +/- SD] yr). Each walked backward for 60 min at 3 km x h(-1) down a 23% grade. Venous blood was sampled before exercise, immediately (0 d) after and 1, 2, 4, and 7 d after exercise for plasma CK assay. @entity925 was evaluated in 18 subjects at selected times during the 7 d postexercise. @entity121 was evaluated by magnetic resonance imaging (MRI). RESULTS: The subjects had high baseline plasma CK activity (187 +/- 127 IU x L(-1); 163 +/- 70 IU x L(-1) with one outlier excluded) compared with typical clinical norms. As a group, CK activity was increased (P < 0.05) 4 d (980 +/- 1331 IU L(-1)) and 7 d (1022 +/- 1031 IU L(-1)) postexercise, compared with preexercise. Eleven (55%) of the subjects had large, delayed increases in plasma CK activity ("hyperresponses"). As a group, the plasma CK response was similar to responses of comparison Caucasian subjects. All subjects reported delayed muscle soreness; there was no association between soreness and plasma CK. Every subject showed MRI evidence of @entity121 but varying in degree and time course. Plasma CK activity correlated to MRI signal intensity (rho = 0.445). CONCLUSION: Results suggest that changes in plasma CK activity and skeletal @entity121 in African-American @entity1 after eccentric exercise do not differ from the responses of Caucasians.
