Abstract
Allergic mediator release inhibitors such as cromolyn sodium have been reported to act by blockade of antigen-induced uptake of extracellular calcium. They also promote the formation of a phosphoprotein during inhibition of mediator release. Since alkaline phosphatase is associated with calcium uptake mechanisms in certain tissues as well as with phosphoprotein phosphatase action, inhibition studies with a series of mediator release inhibitors were done. The mediator release inhibitors, cromolyn sodium, doxantrazole, AA-344, M & B-22948, ICI-74917, and W-13560, were shown to uncompetitively inhibit human leucocyte alkaline phosphatase. The most potent inhibitor, W13560, had a K i of 7.9 × 10 −6 M. Cromolyn sodium was the least effective inhibitor of the series while ICI-74917 and W-13560 were the most potent. Doxantrazole, AA-344, and M & B-22948 were intermediate in their inhibitory activities against alkaline phosphatase. Since uncompetitive inhibitors are known to inhibit, activate, or have no effect on an enzyme, depending upon conditions, the unpredictable clinical activity observed with this class of agent may be explained by their incompetitive nature of inhibition.
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.
