Influence of potent and selective beta-adrenoceptor agonist, CL 316243, on the contractile response of non-pregnant human myometrium.

UNLABELLED: The purpose of this study was to evaluate the effect of beta(3)-adrenoreceptor agonist, CL 316243 on human non-pregnant uterine contractility. The activity of myometrium strips was recorded by means of force transducers with digital output. Quantification of the response of myometrium strips was done by calculation of the area under the curve (AUC), as well as the amplitude and frequency of contractions. CL 316243 in a concentration - dependent manner (10(-10)-10(-4) mol/L) decreased the AUC value (logIC(50) -8.088+/-0.29; n=16). Decreased mean frequency of contractions and nearly 30% inhibition of spontaneous contractile activity were also observed. The inhibition of contractions by CL 316243 was not changed by either butoxamine (selective beta(2)-adrenoreceptor antagonist) or propranolol (beta(1)- and beta(2)-adrenoreceptor antagonist), and was partly antagonized by bupranolol (nonselective beta-adrenoreceptor antagonist), each antagonist at 10(-6) mol/L. IN
CONCLUSION: CL 316243 causes inhibition of spontaneous contractile activity of human non-pregnant myometrium. Our findings also indicate that CL 316243 attenuates the contractile activity of human non-pregnant myometrium by the beta(3)-adrenoreceptors activation.