Browsing by Author "Van Tubbergh, Karen"
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- ItemSkeletal muscle repair after micro-damage : effect of ice therapy on satellite cell activation(Stellenbosch : University of Stellenbosch, 2005-04) Van Tubbergh, Karen; Myburgh, Kathryn H.; Niesler, Carola U.; University of Stellenbosch. Faculty of Science. Dept. of Physiological Sciences.ENGLISH ABSTRACT: Cryotherapy is one of the popular treatments used to alleviate muscle soreness, especially in the competitive sports arena. However, the therapeutic use of cryotherapy is unsubstantiated because of a lack of proper investigations in the literature, especially a hypothesised effect on muscle recovery. Thus, our aims were to characterise satellite cell (SC) activity in human subjects with delayed onset muscle soreness (DOMS) and to shed light on the effect of cryotherapy on SC activity. DOMS was induced in six male subjects (24 ± 3 years) by completion of a downhill-run (DHR) protocol (5 x 8 min bouts, 2 min rest between bouts) at 70 or 80% of their individual peak treadmill speed. Ice application was applied to only one leg per subject for 3 days: 30 min every 2 hours, 5 times per day. In total 5 muscle biopsies were obtained from each subject: 1 baseline and 4 post-DHR. Post-DHR biopsies: 1 from each leg on day 1 and 7 (1st group, n=3) and 1 from each leg on day 2 and 9 (2nd group, n=3). DOMS was successfully induced as indicated by significant increases in muscle soreness at days 1 and 2 post-DHR (P < 0.01), and creatine kinase activity at day 1 post-DHR (P < 0.01). No difference in muscle soreness was found between treated and untreated legs. SC quiescence and activation were characterised by their expression of the cell surface markers CD34 and CD56 respectively. No significant change in quiescent SC was observed in the untreated or treated legs over time. However, at day 1 post-DHR the number of quiescent SC was significantly lower in the untreated compared with the treated leg (P < 0.05). There was a significant increase in activated SC numbers at day 2 post-DHR in the untreated leg, which was sustained up to day 9 post-DHR (P < 0.01). However, no such increase was found in biopsies taken on days 1 and 7. Also, no change was found in the treated leg, however a significant difference between the number of activated SC in untreated and treated legs on days 2 and 9 post-DHR (P < 0.01) was seen. No significant effect of DOMS or ice treatment was observed for the expression of the myogenic regulatory factors, MyoD and myogenin. C2C12 cell cultures induced to differentiate, however, did stain using these antibodies. This is the first study to report an effect of cryotherapy at the tissue level. In conclusion, this study highlights many unanswered questions on the SC response to DOMS at tissue level, and lays a good foundation for future studies.