title: Creatine intake attenuates corticosteroid-induced impairment of voluntary running in hamsters.
abstract: Myopathy is a well-known side effect of corticosteroid therapy. Creatine monohydrate (Cr) supplementation has been shown to increase fat-free mass and muscular function. This study aimed to investigate if Cr administration could offset the deleterious functional effects of high doses of steroids. Fifty-six male Syrian golden hamsters were randomized among 4 groups: GI (n = 10), subcutaneous (s.c.) and intraperitoneal (i.p.) saline; GII (n = 10), s.c. saline and i.p. Cr (600 mg.kg(-1).d(-1)); GIII (n = 18), s.c. dexamethasone (7.5 mg.kg(-1).d(-1)) and i.p. saline; and GIV (n = 18), s.c. dexamethasone and i.p. Cr. Daily voluntary running was measured using activity wheels for 18 d. At the end of the study, statistically significant differences in running were observed between all groups, except for GI versus GII (GI, 8878 +/- 2737 m; GII, 9145 +/- 2000 m; GIII, 4289 +/- 2623 m; GIV, 6339 +/- 2345 m). Dexamethasone led to a significant decrease in cross-sectional area of type II fibers of the medial gastrocnemius. The cross-sectional area of type I fibers was significantly larger in GIV than in GIII. In conclusion, Cr administration attenuated the impairment of daily spontaneous running of hamsters receiving a high dose of corticosteroids. Additional research is needed to clarify the clinical implications of this finding.
authors.affiliation: Medical School of Ribeirão Preto, University of São Paulo, Internal Medicine Department, Hospital das Clínicas de Ribeirão Preto, Avenida Bandeirantes 3900, CEP 14098-900, Brazil.
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Campos
authors.forename: Luciano N
authors.initials: LN
authors.lastname: Serafini
authors.forename: Claudia
authors.initials: C
authors.lastname: Sobreira
authors.forename: Luciana G
authors.initials: LG
authors.lastname: Menezes
authors.forename: José A B
authors.initials: JA
authors.lastname: Martinez
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D003401:Creatine / Q000008:administration & dosage*; D006224:Cricetinae; D003907:Dexamethasone / Q000008:administration & dosage / Q000009:adverse effects; D006651:Histocytochemistry; D008297:Male; D008647:Mesocricetus; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology; D009135:Muscular Diseases / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control*; D012420:Running
chemical_list: D000305:Adrenal Cortex Hormones; D003907:Dexamethasone; D003401:Creatine