Nutritional status influences muscle growth and athletic performance, but little is known about the effect of nutritional supplements, such as creatine, on satellite cell mitotic activity. The purpose of this study was to examine the effect of oral creatine supplementation on muscle growth, compensatory hypertrophy, and satellite cell mitotic activity. Compensatory hypertrophy was induced in the rat plantaris muscle by removing the soleus and gastrocnemius muscles. Immediately following surgery, a group of six rats was provided with elevated levels of creatine monohydrate in their diet. Another group of six rats was maintained as a non-supplemented control group. Twelve days following surgery, all rats were implanted with mini-osmotic pumps containing the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to label mitotically active satellite cells. Four weeks after the initial surgery the rats were killed, plantaris muscles were removed and weighed. Subsequently, BrdU-labeled and non-BrdU-labeled nuclei were identified on enzymatically isolated myofiber segments. Muscle mass and myofiber diameters were larger (P < 0.05) in the muscles that underwent compensatory hypertrophy compared to the control muscles, but there were no differences between muscles from creatine-supplemented and non-creatine-supplemented rats. Similarly, compensatory hypertrophy resulted in an increased (P < 0.05) number of BrdU-labeled myofiber nuclei, but creatine supplementation in combination with compensatory hypertrophy resulted in a higher (P < 0.05) number of BrdU-labeled myofiber nuclei compared to compensatory hypertrophy without creatine supplementation. Thus, creatine supplementation in combination with an increased functional load results in increased satellite cell mitotic activity.
Key words:
Skeletal muscle - overload - bromodeoxyuridine
References
1
Bosco C, Tihanyi J, Pucspk J, Kovacs I, Gabossy A, Colli R, Pulvirenti G, Tranquilli C, Foti C, Viru M, Viru A.
Effect of oral creatine supplementation on jumping and running performance.
Int J Sports Med.
1997;
18
369-372
2
Brannon T A, Adams G R, Coniff C L, Baldwin K M.
Effects of creatine loading and training on running performance and biochemical propertiers of rat skeletal muscle.
Med Sci Sports Exerc.
1997;
29
489-495
3
Casey A, Constantin-Teodosiu D, Howell S, Hultman E, Greenhaff P L.
Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans.
Am J Physiol.
1996;
271
37
6
Green A L, Hultman E, Macdonald I A, Sewell D A, Greenhaff P L.
Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans.
Am J Physiol.
1996;
271
826
8
Harris R C, Soderlund K, Hultman E.
Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation.
Clin Science.
1992;
83
367-374
10 Lehninger A L, Nelson D L, Cox M M. Principles of Biochemistry. Second Edition. New York; Worth Publishers 1993
11
McCall G E, Allen D L, Linderman J K, Grindeland R E, Roy R R, Mukku V R, Edgerton V R.
Maintenance of myonuclear domain size in rat soleus after overload and growth hormone/IGF-I treatment.
J Appl Physiol.
1998;
84
1407-1412
15
Mujika I, Padilla S.
Creatine supplementation as an ergogenic acid for sports performance in highly trained atheltes: a critical review.
Int J Sport Med.
1997;
18
491-496
17 Ott L. An Introduction to Statistical Methods and Data Analysis. Third Edition. Boston; PWS-Kent 1988
18
Rosenblatt J D, Parry D J.
Adaptation of rat extensor digitorum longus muscle to gamma irradiation and overload.
Pflügers Archiv Europ J Physiol.
1993;
423
255-264
19
Roy R R, Talmadge R J, Fox K, Lee M, Ishihara A, Edgerton V R.
Modulation of MHC isoforms in functionally overloaded and exercised rat plantaris fibers.
J Appl Physiol.
1997;
83
280-290
20 SAS Institute. SAS User's Guide: Statistics. Cary NC; SAS Institute 1985
21 Schultz E. Quantification of satellite cells in growing muscle using electron microscopy and fiber whole mounts. In: Mauro A (ed) Muscle Regeneration. New York; Raven 1979: 131-135
23
Sipilä I, Rapola J, Simell O, Vannas A.
Supplementary creatine as a treatment for gyrate atrophy of the choroid and retina.
N Engl J Med.
1981;
304
867-870