Beta3-adrenoceptor is the predominant beta-adrenoceptor subtype in human myometrium and its expression is up-regulated in pregnancy.
Fiche publication
Date publication
mars 2005
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BARDOU Marc
Tous les auteurs :
Rouget C, Bardou M, Breuiller-Fouche M, Loustalot C, Qi H, Naline E, Croci T, Cabrol D, Advenier C, Leroy MJ
Lien Pubmed
Résumé
To assess whether pregnancy might influence the functionality and expression of human myometrial beta(2)- and beta(3)-adrenoceptors (beta(2)- and beta(3)-AR), we performed functional, binding, Western blot, and molecular biology experiments in human nonpregnant and near-term pregnant myometrium. Inhibition of spontaneous contractions induced by a beta(3)-AR agonist, SR 59119A, was significantly greater in pregnant, compared with nonpregnant, myometrial strips (E'(max) = 61 +/- 5% vs. 44 +/- 5% for pregnant and nonpregnant myometrium, respectively), whereas salbutamol, a beta(2)-AR agonist, was significantly less efficient in pregnant, compared with nonpregnant, myometrium (E(max) = 29 +/- 4 vs. 54 +/- 8%). Although two populations of binding sites corresponding to beta(2)- and beta(3)-AR were identified in both nonpregnant and pregnant myometrium, we found a clear predominance of the beta(3)-AR subtype. Moreover, beta(3)-AR binding sites were up-regulated 2-fold in myometrium at the end of pregnancy. Both beta(2)- and beta(3)-AR mRNA were expressed in human nonpregnant and pregnant myometrium. Contrary to beta(2)-AR, the expression of the beta(3)-AR transcripts and immunoreactive proteins was increased in pregnant, compared with nonpregnant, myometrium. Such compelling data suggest a predominant role for beta(3)-AR in the regulation of human myometrium contractility, especially at the end of pregnancy, which might have important consequences for the clinical management of preterm labor.
Référence
J Clin Endocrinol Metab. 2005 Mar;90(3):1644-50