Abstract

AbstractThe relationship between the release of histamine and heparin from rat mast cells exposed to compound 48/80 in vitro has been studied in order to elucidate the mechanism of action of this histamine releasing agent. Heparin is almost exclusively localized to the granule fraction of mast cells and therefore its release can be used as an index of granule release.The ratio percentage histamine release/percentage heparin release was found to be 1.4–1.7 and 1.6–2.0 following exposure of mast cells to 2.5 and 0.25 μg/ml respectively of compound 48/80. These “found” ratios are artificially high due to the fact that it is impossible to effect a complete separation of the released granules from the mast cells. Bearing this in mind, these results are consistent with the hypothesis (Uvnäs and Thon 1966) that the release of histamine‐containing granules is a primary event in the release of histamine induced by this agent. How ever, they do not exclude the possibility that part of the histamine release can take place without granule release. Studies of the specific activities of the 35S‐labelled heparin released and retained by mast cells taken from rats at different intervals after Na235SO4 injection and exposed to compound 48/80 suggest that the most mature granules are released first on treatment of mast cells with this substance.

Full Text
Paper version not known

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 call

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.