אימונים Exercise induced regulation of muscular Na+,K+ pump, FXYD1 and NHE1 mRNA and protein

[Mike Bikov]

Am J Physiol Regul Integr Comp Physiol. 2011 Feb 16. [Epub ahead of print]
Exercise induced regulation of muscular Na+,K+ pump, FXYD1 and NHE1 mRNA and protein expression - importance of training status, intensity and muscle type.

Rasmussen MK, Juel C, Nordsborg NB.

1University of Copenhagen.
Abstract

It is investigated if exercise induced mRNA changes cause similar protein expression changes of Na(+), K(+) pump isoforms (α1, α2, β1, β2), FXYD1 and NHE1 in rat skeletal muscle. Expression was evaluated (n=8 per group) in Soleus and EDL after 1 day, 3 days and 3 weeks (5 sessions per week) of either sprint (4 x 3 min sprint + 1 min rest) or endurance (20 min) running. Two hours after exercise on day 1, no change in protein expression was apparent in either training group or muscle, whereas sprint exercise increased the mRNA of Soleus α2 (4.9±0.8 fold; P<0.05), β2 (13.2±4.4 fold; P<0.001) and NHE1 (12.0±3.1 fold; P<0.01). Two hours after sprint exercise, protein expression normalized to control samples was higher on day 3 than day 1 for Soleus α1 (41±18% increase vs. 15±8% reduction; P<0.05), α2 (64±35% increase vs. 37±12% reduction; P<0.05), β1 (17±21% increase vs. 14±29% reduction; P<0.05) and FXYD1 (35±16% increase vs. 13±10% reduction; P<0.05). In contrast, on day 3, Soleus α1 (0.1±0.1 fold; P<0.001), α2 (0.2±0.1 fold; P<0.001), β1 (0.4±0.1 fold; P<0.05) and β2 (2.9±1.7 fold; P<0.001) mRNA expression was lower than after exercise on day 1. After 3 weeks of training, no change in protein expression relative to control existed. In conclusion, increased expression of Na(+), K(+) pump subunits, FXYD1 and NHE1 after 3 days exercise training does not appear to be an effect of increased constitutive mRNA levels. Importantly, sprint exercise can reduce mRNA expression concomitant with increased protein expression.

PMID: 21325644 [PubMed - as supplied by publisher]​

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