Control of rat tail skin temperature regulation by estrogen receptor-beta selective ligand.

ABSTRACT

OBJECTIVE: To test the role of ERbeta in the control of estrogen-dependent thermoregulation in rats. METHODS: Test the ability of an ERbeta-selective ligand to suppress the elevation in basal rat tail skin temperature (TST) caused by ovariectomy (OVX). RESULTS: ERbeta-19 is a tetrahydrofluorenone ERbeta-selective ligand that displaces 0.1 nM estradiol from ERbeta with an IC50 of 1.8 nM compared to an IC50 of 141 nM for ERalpha. Like estradiol, it acts as an agonist on ERbeta-mediated transactivation and transrepression with 25- and 60-fold selectivity, respectively, over ERalpha-controlled transcription. Administration of estradiol to estrogen-depleted rats suppresses the ovariectomy-induced elevation of TST. Similar treatment of OVX rats with ERbeta-19 also results in suppression of elevated TST. However, in contrast to estradiol, ERbeta-19 does not suppress body weight, does not increase uterine weight, nor does it stimulate uterocalin biomarker expression which is under the control of ERalpha. Thus, the ERbeta-19 suppression of rat TST is mediated by ERbeta without eliciting the activity of ERalpha. CONCLUSION: Estrogen-sensitive thermoregulation in ovariectomized rats can be controlled by an ERbeta-selective ligand.