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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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EFFECTS OF HIGH-DOSE CREATINE SUPPLEMENTATION ON KIDNEY AND LIVER RESPONSES IN SEDENTARY AND EXERCISED RATS |
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Renato A. Souza1,2  ,
Humberto Miranda1, Murilo Xavier1,2, Rodrigo A. Lazo-Osorio1,
Hélio A. Gouvea1, José C. Cogo1, Rodolfo P. Vieira3
and Wellington Ribeiro1 |
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1Laboratory of Physiology and Pharmacodynamic, Institute of Research and Development, University of Vale do Paraíba, São José dos Campos, SP, Brazil, 2Department of Physical Therapy, University of Vales do Jequitinhonha e Mucuri, Diamantina, MG, Brazil, 3COPD & Asthma Research Group (CARG), Department of Pneumology, University Hospital Freiburg, Freiburg, Germany, and Department of Pathology (LIM 05), School of Medicine, University of São Paulo (USP), São Paulo, SP, Brazil. |
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© Journal of Sports Science and Medicine (2009) 8, 672 - 681 |
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| ABSTRACT | |||
| This study evaluated the effects of high-dose of short-term creatine
supplementation (5g.kg-1.day-1 to 1 week) and long-term creatine supplementation
(1g.kg-1. day-1 to 4-8 weeks) on kidney and liver structure and function
of sedentary and exercised Wistar rats (Exercise sessions consisted of swimming
at 80% of maximal work load supported during 5 days per week with daily
sessions of 60 minutes throughout the duration of the supplementation).
Seventy- two animals (245 ± 5g) were divided into four groups (n = 18):
control diet Sedentary (SED), Creatine diet Sedentary (CRE), control diet
Exercised (EXE), and Creatine diet Exercised (EXECRE). Histological and
blood biochemical studies were performed after one, four, and eight weeks
of creatine supplementation and exercise (n = 6). No differences were found
when comparing SED, EXE and EXECRE groups for kidney and liver structure
and function at one, four and eight weeks. However, the CRE group showed
higher levels of creatinine (1.1 ± 0.2 vs. 0.4 ± 0.1 mg.dl-1; p < 0.05),
and urea (37 ± 3 vs. 19 ± 1 mg.dl-1; p < 0.05) when compared with all
others groups at four and eight weeks. At eight weeks, the CRE group presented
increased levels of ALT (41 ± 7 vs. 23 ± 7 U.L-1; p < 0.05), AST (89
± 6 vs. 62 ± 5 U.L-1; p < 0.05), GGT (8.0 ± 0.9 vs. 3.9 ± 1.0 U.L-1;
p < 0.05), and AP (125 ± 10 vs. 69 ± 9 U.L-1; p < 0.05) also when
compared with all others groups. Moreover, the CRE group demonstrated some
structural alterations indicating renal and hepatic damage at four and eight
weeks, respectively. These results suggest that long-term creatine supplementation
(up to 4-8 weeks) may adversely affect kidney and liver structure and function
of sedentary but not of exercised rats.
Key words: Creatine monohydrate, hepatic metabolism, kidney metabolism, swimming training, sports supplements, toxicology. |
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