Schwane J A, Buckley R T, Dipaolo D P, Atkinson M A, Shepherd J R
Department of Health and Kinesiology, The University of Texas at Tyler and The University of Texas Health Center at Tyler, 75799, USA.
Med Sci Sports Exerc. 2000 Feb;32(2):370-8. doi: 10.1097/00005768-200002000-00017.
The primary aim was to describe the response of plasma creatine kinase (CK) activity in a sample of African-American men after a bout of eccentric exercise. The study also described signal intensity changes detected by MR in the musculature of the right lower leg.
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. Soreness in the plantar flexor muscles was evaluated in 18 subjects at selected times during the 7 d postexercise. Injury to the plantar flexor muscles was evaluated by magnetic resonance imaging (MRI).
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 injury to plantar flexor muscles postexercise but varying in degree and time course. Plasma CK activity correlated to MRI signal intensity (rho = 0.445).
Results suggest that changes in plasma CK activity and skeletal muscle injury in African-American men after eccentric exercise do not differ from the responses of Caucasians.
主要目的是描述一组非裔美国男性在一次离心运动后血浆肌酸激酶（CK）活性的反应。该研究还描述了通过磁共振成像（MR）检测到的右小腿肌肉组织信号强度变化。
受试者为20名非洲裔男性志愿者（年龄 = 24 ± 4 [平均值 ± 标准差]岁）。每个人以3 km·h⁻¹的速度在23%的坡度上向后行走60分钟。在运动前、运动后即刻（0天）以及运动后1、2、4和7天采集静脉血用于血浆CK检测。在运动后7天内的特定时间，对18名受试者的跖屈肌酸痛情况进行评估。通过磁共振成像（MRI）评估跖屈肌的损伤情况。
与典型临床标准相比，受试者的血浆CK活性基线较高（187 ± 127 IU·L⁻¹；排除一个异常值后为163 ± 70 IU·L⁻¹）。作为一个整体，与运动前相比，运动后4天（980 ± 1331 IU·L⁻¹）和7天（1022 ± 1031 IU·L⁻¹）CK活性升高（P < 0.05）。11名（55%）受试者的血浆CK活性出现大幅延迟升高（“高反应”）。作为一个整体，血浆CK反应与对照白人受试者的反应相似。所有受试者均报告有延迟性肌肉酸痛；酸痛与血浆CK之间无关联。每个受试者运动后均显示MRI有跖屈肌损伤的证据，但程度和时间进程各不相同。血浆CK活性与MRI信号强度相关（rho = 0.445）。
结果表明，非裔美国男性在离心运动后血浆CK活性变化和骨骼肌损伤情况与白人的反应无差异。
