TY - JOUR
T1 - Acute exercise activates local bioactive androgen metabolism in skeletal muscle
AU - Aizawa, Katsuji
AU - Iemitsu, Motoyuki
AU - Maeda, Seiji
AU - Otsuki, Takeshi
AU - Sato, Koji
AU - Ushida, Takashi
AU - Mesaki, Noboru
AU - Akimoto, Takayuki
N1 - Funding Information:
This work was supported by grants-in-aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (21300254 and 203903). We thank Dr. Robert DiGiovanni (Waseda University, Tokyo, Japan) for critical review and editing of the manuscript.
PY - 2010/3
Y1 - 2010/3
N2 - Androgens, such as testosterone, play important roles in regulation of diverse physiological process of target tissues. Recently, we reported that steroidogenic enzymes exist in skeletal muscle and regulate local production of testosterone in response to exercise. Testosterone is transformed into a bioactive androgen metabolite, dihydrotestosterone (DHT) by 5α-reductase. However, it is unclear whether exercise stimulates local bioactive androgen metabolism in the skeletal muscle in both sexes. In the present study, we examined sex differences in the levels of dehydroepiandrosterone (DHEA), free testosterone, DHT, and steroidogenesis-related enzymes 5α-reductase and androgen receptor (AR) in rat's skeletal muscle before and after a single bout of exercise. Basal muscular free testosterone and DHT levels were higher in males than females, whereas the levels of DHEA did not differ between the sexes. Muscular DHEA, free testosterone, and DHT levels were increased in both sexes after the exercise. There were no differences of 5α-reductase and AR transcripts and proteins between the sexes, and the expression of 5α-reductase was significantly increased in both sexes after the exercise. Finally, the expression of AR was significantly higher in female rats, but not in males after the exercise. These data suggest that acute exercise enhances the local bioactive androgen metabolism in the skeletal muscle of both sexes.
AB - Androgens, such as testosterone, play important roles in regulation of diverse physiological process of target tissues. Recently, we reported that steroidogenic enzymes exist in skeletal muscle and regulate local production of testosterone in response to exercise. Testosterone is transformed into a bioactive androgen metabolite, dihydrotestosterone (DHT) by 5α-reductase. However, it is unclear whether exercise stimulates local bioactive androgen metabolism in the skeletal muscle in both sexes. In the present study, we examined sex differences in the levels of dehydroepiandrosterone (DHEA), free testosterone, DHT, and steroidogenesis-related enzymes 5α-reductase and androgen receptor (AR) in rat's skeletal muscle before and after a single bout of exercise. Basal muscular free testosterone and DHT levels were higher in males than females, whereas the levels of DHEA did not differ between the sexes. Muscular DHEA, free testosterone, and DHT levels were increased in both sexes after the exercise. There were no differences of 5α-reductase and AR transcripts and proteins between the sexes, and the expression of 5α-reductase was significantly increased in both sexes after the exercise. Finally, the expression of AR was significantly higher in female rats, but not in males after the exercise. These data suggest that acute exercise enhances the local bioactive androgen metabolism in the skeletal muscle of both sexes.
KW - 5α-reductase
KW - Acute exercise
KW - Androgen receptor
KW - Dihydrotestosterone
KW - Skeletal muscle
KW - Testosterone
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U2 - 10.1016/j.steroids.2009.12.002
DO - 10.1016/j.steroids.2009.12.002
M3 - Article
C2 - 20045012
AN - SCOPUS:76349111558
SN - 0039-128X
VL - 75
SP - 219
EP - 223
JO - Steroids
JF - Steroids
IS - 3
ER -