Abstract
Polyphloretin phosphate (PPP) produced a dose-dependent decrease in the tone and reduction of the spontaneous phasic contactions of the longitudinal muscle of guinea-pig isolated ileum. PPP (100 microgram ml-1) after a 2 min contact with the ileum decreased the contractile effects of PGE1 0.1 micron by 40.6 +/- 7.4%, of PGE1 0.01 micron by 86.7 +/- 3.3% and of PGE2alpha 0.1 micron by 62.2 +/- 8.6%. After 10 min contact of PPP the contractile effect of PGE1 0.1 micron was decreased by 47.7 +/- 4.7% and that of PGE2alpha 0.1 micron by 89.6 +/- 1.7%. When the contact was longer, PPP showed a pronounced after-effect in respect to the effects of PGE1 and particularly of PGF2alpha. PPP signicantly reduced contractions to 5-HT and BaCL2, but not to acetylcholine, histamine or substance P. The type of antagonism of PGE1 by PPP was examined using cumulative concentration-effect curves for PGE1 in the presence of increasing concentrations of PPP. We conclude that on guinea-pig ileum PPP acts as a non-competitive antagonist of PGE1 and PGF2alpha.
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.
