Drug inhibition of anaphylactic histamine release from peritoneal cells of rats infected with Toxocara canis.

An experimental model for studying anaphylactic histamine release from rat peritoneal cells in vitro is described. Rats were sensitized by feeding the infective eggs of ttoxocara canis, the antigen being prepared from the infective eggs. The characteristics of histamine release are comparable with those found for other anaphylactic systems. Addition of 0.2% inactivated normal rat serum to the incubation media reduced the spontaneous histamine release from 11.5 +/- 1.9% to 3.1 +/- 1.6% (mean +/- SD) of total histamine, whereas the corresponding figure for anaphylactic histamine release was 41.3 +/- 19.7%. Both disodium cromoglycate (DSCG) and levamisole produced a dose-related inhibition of histamine release, with DSCG being the more potent drug.