Abstract
Contractions of isolated strips of human umbilical artery (HUA) induced by arachidonic acid were antagonized by indomethacin at concentrations as low as 1 microgram/ml. Much higher concentrations (25 and 65 microgram/ml) were needed to relax KCl-contracted strips of HUA. These data suggest that indomethacin at 1 microgram/ml inhibits endogenous synthesis of vasoconstrictive prostaglandin-like substances whereas indomethacin at higher concentrations causes nonspecific relaxation. Contractions induced by 5-hydroxytryptamine (5-HT), KCl and prostaglandin F2 alpha (PGF2 alpha) were antagonized by indomethacin at 25 and 65 microgram/ml, but not at 2.5 microgram/ml. These data suggest that the contractile responses to 5-HT, KCl and PGF2 alpha are not mediated by endogenous prostaglandin-like substances. Contractions induced by adenosine triphosphate (ATP), in contrast, were completely inhibited by indomethacin (1 microgram/ml). Therefore, the data suggest that prostaglandin-like substances may mediate contractions to ATP.
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.
