Specific adaptations of estrogen receptor alpha and beta transcripts in liver and heart after endurance training in rats.
Estrogens exert their biological roles mainly through estrogen receptors (ER) that function as ligand-activated transcription factors. ER content in a cell is regulated by many factors and is decisive for estrogen action. The purpose of the present study was to investigate the influence of an 8-wk endurance training program on ER expression in the liver, right atrium (RA), and left ventricle (LV) of intact and ovariectomized (Ovx) rats. We measured ERalpha and ERbeta mRNA content by reverse transcription-polymerase chain reaction (RT-PCR). We found an important increase in ERalpha mRNA levels in the liver (300%; P < 0.01) and in ERbeta mRNA levels in the RA (200%; P < 0.05), and a marked decrease in ERalpha (80%; P < 0.01) and ERbeta (40%; P < 0.05) transcripts content in the LV of intact rats after endurance training. On the other hand, ERalpha mRNA levels were depressed by 50% (P < 0.01) in the liver, and increased by 60% (P < 0.01) in LV of Ovx rats after exercise training. These results first indicate that endurance training is associated with modifications of ER transcripts levels in the liver, LV, and RA of female rats. More specifically, these effects are tissue and isoform-specific and the direction of the response (increase or decrease) is different in intact and Ovx rats. It is suggested that some of the adaptations to endurance training in liver and heart may be mediated by an ER-dependent mechanism.
Département de kinésiologie, Université de Montréal, C.P. 6128, Succ. centre-ville, Montreal, QC, Canada H3C 3J7.
Amélie
A
Paquette
Dongaho
D
Wang
Marie-Soleil
MS
Gauthier
Denis
D
Prud'homme
Marek
M
Jankowski
Jolanta
J
Gutkowska
Jean-Marc
JM
Lavoie
D000818:Animals; D047628:Estrogen Receptor alpha / Q000235:genetics*; D047629:Estrogen Receptor beta / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006325:Heart Atria / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D010052:Ovariectomy; D010805:Physical Conditioning, Animal; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger