Abstract
The selective 5-HT2 receptor blocker ketanserin was found to reduce maximal urethral pressures in healthy females by about 40% without reducing blood pressure. In vitro, ketanserin completely or almost completely reduced contractions of the isolated female rabbit urethra induced by phenylephrine, noradrenaline (NA) and electrical field stimulation. The drug was less effective against responses evoked by Clonidine and 5-hydroxytryptamine (5-HT). 5-HT-induced contractions were effectively reduced by methysergide, but little affected by prazosin and rauwolscine. In concentrations exceeding 10−7 M ketanserin significantly increased efflux of 3H in 3H-NA preloaded preparations of rabbit urethral muscle. Low concentrations of 5-HT, 10−6 M, had slight inhibitory effects of 3H release, whereas 5-HT 10−5 M caused a significant increase. It is concluded that ketanserin counteracts the effects of postjunctional α1-adrenoceptor stimulation in isolated rabbit urethra. Such an effect might also explain its urethral pressure lowering action in man.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
