Effect of ovariectomy on renal estrogen receptor-alpha and estrogen receptor-beta in young salt-sensitive and -resistant rats.
This study evaluated the effect of ovariectomy on renal estrogen receptor (ER)-alpha and ERbeta expression in young female Dahl salt-sensitive and salt-resistant rats. Our hypothesis was that estrogen depletion results in an imbalance in ERalpha and ERbeta expression in salt-sensitive rats. Rats were subjected to sham surgery (intact), ovariectomy, and ovariectomy with estrogen replacement. Kidneys were harvested 8 weeks later. Western blot was used to measure ERalpha and ERbeta expression in the cortex and medulla. In intact rats, ERalpha was 2.7- and 4.3-fold higher in salt-sensitive compared with salt-resistant rats in the renal cortex and medulla, respectively. In salt-sensitive rats, ovariectomy caused 42% and 52% decreases in ERalpha and 107% and 314% increases in ERbeta in renal cortex and medulla, respectively. In salt-resistant rats, ovariectomy caused 33% and 150% increases in ERalpha and 107% and 100% increases in ERbeta in renal cortex and medulla, respectively. Estrogen replacement did not alter ERalpha but restored ERbeta expression levels similar to levels in intact rats in both salt-sensitive and salt-resistant rats. Thus, estrogen loss had opposite effects on ERalpha in salt-sensitive (downregulation) and salt-resistant rats (upregulation). We propose that the decrease in ERalpha expression in salt-sensitive rats after estrogen loss alters the balance of renal ERs and may play a role in accelerating the development of hypertension and renal damage.
Esqueda
Maria Eugenia Davila
ME
Department of Anesthesiology, University of Texas Health Science Center, 7703 Floyd Curl Dr, San Antonio, TX 78229-3900, USA.
Craig
Teresa
T
Hinojosa-Laborde
Carmen
C
D000818:Animals; D004195:Disease Models, Animal; D015536:Down-Regulation; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000502:physiology*; D005260:Female; D006973:Hypertension / Q000209:etiology / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism; D010052:Ovariectomy; D051381:Rats; D020303:Rats, Inbred Dahl; D015854:Up-Regulation
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens