[Suppression by bone marrow cells of the level of specific IgE antibodies in the blood of mice and decrease in the production of IGE by bone marrow cells].

Changes in the level of the specific IgE-antibodies to ovalbumin under the influence of syngeneic cells of a bone marrow were studied. The IgE-response was induced by ovalbumin in mice (CBA X C57Bl/6)F1. The bone marrow cells suspensions (20-30 X 10(6) cells per mouse) from syngeneic donors was inoculated simultaneously with the immunization.

[Histamine release from human leukocytes after treatment with 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) and its structural analogs].

The influence of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, a platelet activating factor (PAF), and its structural analogs--1-acyl-2-acetyl-sn-glycero-3-phosphocholine and 1-(1'-alkenyl)-glycero-3-phosphocholine--on the histamine release from human leukocytes of healthy and allergic individuals was investigated. It was found that within the concentration range of 10(-10) to 10(-7) M PAF and its analogs induce a moderate histamine release from the leukocytes. However, at higher concentrations (greater than 10(-7) M) PAF induces an enhanced release of histamine from the leukocytes of allergic patients as compared to healthy individuals.