Human muscle gene expression following resistance exercise and blood flow restriction.
BACKGROUND
Blood flow restriction in combination with low-intensity resistance exercise (REFR) increases skeletal muscle size to a similar extent as compared with traditional high-intensity resistance exercise training. However, there are limited data describing the molecular adaptations that occur after REFR.


OBJECTIVE
To determine whether hypoxia inducible factor-1 alpha (HIF-1alpha) and REDD1 mRNA are expressed differently in REFR compared with low-intensity resistance exercise with no blood flow restriction (CONTROL). Secondly, to determine whether low-intensity resistance exercise is able to induce changes in mRNA expression of several anabolic and catabolic genes as typically seen with high-intensity resistance exercise.


METHODS
Six subjects were studied at baseline and 3 h after a bout of leg resistance exercise (20% 1RM) in REFR and CONTROL subjects. Each subject participated in both groups, with 3 wk separating each visit. Muscle biopsy samples were analyzed for mRNA expression, using qRT-PCR.


RESULTS
Our primary finding was that there were no differences between CONTROL and REFR for any of the selected genes at 3 h after exercise (P > 0.05). However, low-intensity resistance exercise increased HIF-1alpha, p21, MyoD, and muscle RING finger 1 (MuRF1) mRNA expression and decreased REDD1 and myostatin mRNA expression in both groups (P < 0.05).


CONCLUSIONS
Low-intensity resistance exercise can alter skeletal muscle mRNA expression of several genes associated with muscle growth and remodeling, such as REDD1, HIF-1alpha, MyoD, MuRF1, and myostatin. Further, the results from REFR and CONTROL were similar, indicating that the changes in early postexercise gene expression were attributable to the low-intensity resistance exercise bout, and not blood flow restriction.
Drummond
Micah J
MJ
Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, USA.
Fujita
Satoshi
S
Abe
Takashi
T
Takashi
Abe
A
Dreyer
Hans C
HC
Volpi
Elena
E
Rasmussen
Blake B
BB
D000222:Adaptation, Physiological; D000328:Adult; D016022:Case-Control Studies; D018592:Cross-Over Studies; D015870:Gene Expression; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology*; D055435:Myostatin; D011446:Prospective Studies; D011494:Protein Kinases; D012333:RNA, Messenger / Q000235:genetics; D015424:Reperfusion; D058570:TOR Serine-Threonine Kinases; D016212:Transforming Growth Factor beta; D014891:Weight Lifting / Q000502:physiology*
C525911:MSTN protein, human; D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D011494:Protein Kinases; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases