The Release of Histamine from Rabbit Platelets by Means of Antigen-Antibody Precipitates

Abstract

Summary: Not all rabbit platelets and/or plasma possess the same capacity to release histamine when exposed to immune precipitates. The variability in ability to support histamine release can also be demonstrated with plasma and platelets from the same rabbit tested on different days. Precipitates prepared from rabbit antisera are more effective in histamine release than those from horse and sheep antisera. When the precipitate weight is above 200 μg of nitrogen, there is a direct relationship between composition of precipitate and histamine release. The greater the antibody-antigen ratio, the greater the histamine release. The capacity of an antigen-antibody system to release histamine does not correlate with its complement-fixing ability.