Castration reduces mRNA levels for calcium regulatory proteins in rat heart.
Sex-related differences in the cardiac phenotype have been well established. This study was designed to determine whether androgens regulate myocardial gene expression and play a role in the sex-related differences in the myocardial phenotype. Gonadectomized male rats were treated with testosterone, and myocardial gene expression was examined in whole heart using quantitative real-time PCR. Gonadectomy produced a substantial decrease in mRNA levels for the androgen receptor, Na(+)/Ca(2+) exchanger, L- type calcium channel, and beta(1)-adrenergic receptor (beta(1)AR). Supplementation of testosterone in castrates produced a fivefold increase in androgen receptor mRNA levels. Testosterone treatment of castrates produced almost a sixfold increase in Na(+)/Ca(2+) exchanger mRNA, a tenfold increase in Ltype calcium channel mRNA accumulation, and a fourfold increase in beta(1)AR mRNA levels. Increased calcium channel expression, beta(1)AR expression, and Na(+)/Ca(2+) exchanger expression together may alter cytosolic calcium. These results provide the first evidence that testosterone regulates expression of myocardial calcium regulating genes and thus may play a role in modulating the cardiac phenotype in males.
Golden
Kish L
KL
Department of Physiology, Wayne State University, Detroit, MI 48201, USA. kgolden@med.wayne.edu
Marsh
James D
JD
Jiang
Yang
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D006321:Heart / Q000033:anatomy & histology; D008297:Male; D009206:Myocardium / Q000737:chemistry*; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics*; D011944:Receptors, Androgen / Q000235:genetics*; D019831:Sodium-Calcium Exchanger / Q000235:genetics*; D013739:Testosterone / Q000494:pharmacology
D020746:Calcium Channels, L-Type; D012333:RNA, Messenger; D018342:Receptors, Adrenergic, beta-1; D011944:Receptors, Androgen; D019831:Sodium-Calcium Exchanger; D013739:Testosterone; D002118:Calcium