Please use this identifier to cite or link to this item:
|Title:||Combined walking exercise and alkali therapy in patients with CKD4-5 regulates intramuscular free amino acid pools and ubiquitin E3 ligase expression.|
|Authors:||Watson, Emma L.|
Kosmadakis, George C.
Smith, Alice C.
Viana, Joao L.
Brown, Jeremy R.
Pawluczyk, Izabella Z.
Bishop, Nicolette C.
Maughan, Ronald J.
Owen, Paul J.
John, Stephen G.
McIntyre, Christopher W.
|Citation:||European Journal of Applied Physiology and Occupational Physiology, 2013, available online in advance of print|
|Abstract:||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.|
|Rights:||Copyright © Springer-Verlag Berlin Heidelberg 2013. Deposited with reference to the publisher's archiving policy available on the SHERPA/RoMEO website. The final publication is available at http://link.springer.com/article/10.1007%2Fs00421-013-2628-5|
|Appears in Collections:||Published Articles, Dept. of Infection, Immunity and Inflammation|
Files in This Item:
|Watson_et_al_in press 2013.pdf||Post-review (final submitted)||894.65 kB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.