Microarray analysis of skeletal muscle hypertrophy induced by heat-stress in healthy humans

This study was aimed at examining the effects of long-term of heat-stress on the gene expression of skeletal muscle hypertrophy. Heat- and stream-generating (HSG) sheets were placed on thigh laterally. The HSG sheets (heat-stress) were applied 8-hrs/day, once a day, 4 days/weeks, for 10 weeks. A muscle biopsy was taken from the vastus lateralis muscle (2 cm depth) of the treated leg before and after the experiment. Oligonucleotide microarray revealed that genes related to ATP-synthesis, protein synthesis and the molecular chaperonic activity were increased by heat stress. These results suggest that heat-stress might be a useful countermeasure for muscular atrophy during aging. Overall design Five subjects were applied by heat- and stream-generating (HSG) sheets for 10 weeks. Total RNAs obtained from the skeletal muscle before and after the experiment were used for the analysis.