Abstract
The potency of the antipsychotic drug, risperidone, to antagonize α 1A-adrenoceptor-mediated contraction in rat vas deferens and vasoconstriction in rat perfused kidney, and α 1B-adrenoceptor-mediated contractions in spleen from guinea-pig and mouse was evaluated and compared to that of α 1-adrenoceptor subtype-discriminating antagonists. Prazosin was found to be unselective; 2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane (WB 4101), 5-methyl-urapidil, indoramin and (+)-niguldipine were confirmed as selective for the α 1A-adrenoceptor, whereas spiperone was weakly α 1B-selective. Risperidone was equipotent to prazosin at α 1A-adrenoceptors in rat vas deferens and kidney. However, at guinea-pig and mouse splenic α 1B-adrenoceptors, the affinity values of risperidone were 10-fold lower than those of prazosin. Thus, in functional experiments the presumed high selectivity of risperidone for the B subtype of α 1-adrenoceptors could not be confirmed, the drug instead appears to be moderately selective (10-fold) for the A subtype.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.