The effect of nebivolol on spontaneous, oxytocin and prostaglandin f2alpha induced contractions of isolated rat myometrium

2.ABSTRACTThe Effect Of Nebivolol On Spontaneous, Oxytocin And Prostaglandin F2αInduced Contractions Of Isolated Rat MyometriumPreterm delivery, despite showing differences between communities constitutesapproximately 10% of all deliveries. In premature infants central nervous systemdevelopment defects, pulmoner system disfunction and ophthalmologic problemsare observed in long term follow up. Since premature infants need special careand cause social, phsychiotic and economic problems to the family, socialdimension of the situation also becomes important. In addition, drugs used for thispurpose are far away from completely preventing the premature delivery. Newtreatment protocols should be investigated for this purpose.In this study, we examined the effect of nebivolol which is a selective betablocker on the isolated rat myometrium which are contracted spontaneously, withoxytocin or prostaglandin F2α in isolated organ bath.From upper poles of thirty rat uterus, 1x0.2x0.2 cm measuring myometriumsections are obtained. In isolated organ bath spontaneous contractions occuringafter one grams strech oxytocin and prostaglandin F2α induced contractions arerandomly divided into 3 groups. In G1 (n=7), after induction of spontaneouscontractions, in G2 (n=8) after induction of contractions with 1µM oxytocin andin G3 (n=9) after induction of contractions with 1µM prostaglandin F2α, 50, 250,13500 µM nebivolol were added to the bath respectively and tocolytic effects wereexamined.Wilcoxon Rank Test was used to evaluate data in each group and MannWhitney-U test to evaluate data between groups and statistical evaluation wasdone by Microgal Origin 6.0 SPSS 10.0 computer programme.Nebivolol significantly and dose dependently inhibited the peak amplitude andarea under curve of all the contractions; spontaneous, oxytocin and prostaglandinF2α induced (p<0.05, Wilcoxon Rank Test). Statistically significant inhibition infrequency of contraction is observed with 250 and 500 µM doses in group 1 andwith all doses in group 2 (p<0.05 Wilcoxon Rank Test). No statisticallysignificant difference was observed in the frequency of contractions in group 3.In conclusion, nebivolol -a selective beta 1 bloker-suppressed thespontaneous, oxytocin and prostaglandin F2α induced contractions and is found tobe significantly effective. The clinical efficiency, maternal and fetal effects shouldbe examined and results must be compared with the tocolytic treatments currentlyused. As a result of all these nebivolol may be an alternative tocolytic agent infuture.Key words: Premature delivery, tocolysis, nebivolol14