Human Muscle Gene Expression following Resistance Exercise and Blood Flow Restri

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Med Sci Sports Exerc. 2008 Feb 29

Human Muscle Gene Expression following Resistance Exercise and Blood

Flow Restriction.

Drummond MJ, Fujita S, Takashi A, Dreyer HC, Volpi E, Rasmussen BB.

1Departments of Physical Therapy and 2Internal Medicine and 3Division

of Rehabilitation Sciences, University of Texas Medical Branch,

Galveston, TX; and 4Department of Human and Engineered Environmental

Studies, Graduate School of Frontier Sciences, University of Tokyo,

Chiba, JAPAN.

INTRODUCTION:: 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.

PURPOSE:: 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).

CONCLUSION:: 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.