Comparative and functional analysis of β-adrenoceptors in human myometrium

Abstract

There are three subtypes of the β-adrenoceptors (β1, β2 and β3). All the β-adrenoceptor subtypes couple to Gαs subunit of G protein. All the β-adrenoceptor subtypes couple mainly to Gαs subunit of G protein. β2-adrenoceptor agonists have been used clinically to suppress myometrial contractions during the management of preterm labour. β2-adrenoceptor agonists lose their effectiveness in a short time and their use causes several side effects. Evidence in the literature supports the expression of functional β2- and β3-adrenoceptors in the lower pregnant human myometrial tissues. However, no definitive understanding in terms of regional and temporal expression and function of the β-adrenoceptors in the uterus was obtained by reviewing the literature. Experiments of this work have confirmed the expression of the three β-adrenoceptor subtypes in term pregnant (upper and lower) human myometrial tissues by real-time RT-PCR analysis. Poor antibody specificity was an obstacle to determine and localize the β-adrenoceptor proteins in the myometrium by immunohistochemistry. β2- and β3-adrenoceptor agonists did not affect the expression of CRISPLD2, RGS2 and NA4A3 in primary MSM cells after 2 and 6 h of incubation. Further research must be done to determine and localize the expression of the β-adrenoceptors in the myometrium.