Detalhes bibliográficos
| Resumo: | Muscle-wasting in chronic kidney disease (CKD) arises from several factors including sedentary behaviour and metabolic acidosis. Exercise is potentially beneficial but might worsen acidosis through exercise-induced lactic acidosis. We studied the chronic effects of exercise in CKD stage 4-5 patients (brisk walking, 30 min, 5 times/week), and non-exercising controls; each group receiving standard oral bicarbonate (STD), or additional bicarbonate (XS) (Total n = 26; Exercising + STD n = 9; Exercising +XS n = 6; Control + STD n = 8; Control + XS n = 3). Blood and vastus lateralis biopsies were drawn at baseline and 6 months. The rise in blood lactate in submaximal treadmill tests was suppressed in the Exercising + XS group. After 6 months, intramuscular free amino acids (including the branched chain amino acids) in the Exercising + STD group showed a striking chronic depletion. This did not occur in the Exercising + XS group. The effect in Exercising + XS patients was accompanied by reduced transcription of ubiquitin E3-ligase MuRF1 which activates proteolysis via the ubiquitin-proteasome pathway. Other anabolic indicators (Akt activation and suppression of the 14 kDa actin catabolic marker) were unaffected in Exercising + XS patients. Possibly because of this, overall suppression of myofibrillar proteolysis (3-methylhistidine output) was not observed. It is suggested that alkali effects in exercisers arose by countering exercise-induced acidosis. Whether further anabolic effects are attainable on combining alkali with enhanced exercise (e.g. resistance exercise) merits further investigation. |
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| Autores principais: | Watson, Emma L. |
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| Outros Autores: | Kosmadakis, George C.; Smith, Alice C.; Viana, Joao L.; Brown, Jeremy R.; Molyneux, Karen; Pawluczyk, Izabella Z. A.; Mulheran, Michael; Bishop, Nicolette C.; Shirreffs, Susan; Maughan, Ronald J.; Owen, Paul J.; John, Stephen G.; McIntyre, Christopher W.; Feehally, John; Bevington, Alan |
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| Assunto: | Adult Aged Aged, 80 and over Amino Acids Bicarbonates Combined Modality Therapy Female Humans Lactic Acid Male Middle Aged Muscle Proteins Muscle, Skeletal Proto-Oncogene Proteins c-akt Renal Insufficiency, Chronic Tripartite Motif Proteins Ubiquitin-Protein Ligases Exercise Therapy Walking |
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| Ano: | 2013 |
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| País: | Portugal |
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| Tipo de documento: | artigo |
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| Tipo de acesso: | acesso aberto |
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| Instituição associada: | UMaia |
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| Idioma: | inglês |
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| Origem: | Repositório Científico da UMaia |
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