Selective estrogen receptor-alpha agonist provides widespread heart and vascular protection with enhanced endothelial progenitor cell mobilization in the absence of uterotrophic action.
The beneficial effects of estrogens on the cardiovascular system are associated with adverse effects on reproductive tissues. On the basis of previous work indicating a major role for estrogen receptor (ER)-alpha in maintaining cardiovascular health, we evaluated the tissue selectivity of the ER alpha-selective agonist propyl pyrazole triol (PPT) compared with 17beta-estradiol (E2) in vivo. Four weeks postovariectomy, equimolar doses of PPT and E2 were administered to rats in subcutaneous implants for 5 d. Both treatments restored rapid vasorelaxation of aortic tissue to estrogenic agents and prevented coronary hyperresponsiveness to angiotensin II in isolated heart preparations. Accordingly, multiple endpoints of myocardial ischemia-reperfusion injury exacerbated by ovariectomy returned to baseline following treatment. These protective effects were linked to increased in vivo levels of endothelial progenitor cells (EPCs). Human EPC function was enhanced in vitro after PPT treatment. In sharp contrast to E2, PPT treatment had no effect on uterine weight and histomorphology except for vessel density, and failed to up-regulate classic estrogen target genes. Dissection of the effects on vascular reactivity and uterine morphology was also observed following increased exposure to PPT at a higher dose for longer time. These data provide the first in vivo evidence for tissue-specific ER alpha activation. By conferring cardiovascular protection dissected from unwanted uterotrophic effects, ER alpha-selective agonists may represent a potential safer alternative to natural hormones.
Bolego
Chiara
C
Department of Pharmacology and Anesthesiology, University of Padua, Largo Meneghetti 2, 35131 Padua, Italy. chiara.bolego@unipd.it
Rossoni
Giuseppe
G
Fadini
Gian Paolo
GP
Vegeto
Elisabetta
E
Pinna
Christian
C
Albiero
Mattia
M
Boscaro
Elisa
E
Agostini
Carlo
C
Avogaro
Angelo
A
Gaion
Rosa Maria
RM
Cignarella
Andrea
A
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000502:physiology; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002319:Cardiovascular System / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000819:agonists*; D005260:Female; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D010636:Phenols; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects
D002316:Cardiotonic Agents; D047628:Estrogen Receptor alpha; D010636:Phenols; D011720:Pyrazoles; C486184:4,4',4''-(4-propyl-((1)H)-pyrazole-1,3,5-triyl) tris-phenol; D000804:Angiotensin II; D004958:Estradiol