[Effect of vitamin A on the in vitro degranulation of mouse mast cells]

The present paper analyses the effect of vitamin A on the degranulation of mouse peritoneal mast cells, considering that the vitamin A has a labilizing effect on the lysosome membrane and that also may regulate the mucopolysaccharides synthesis, which are present in the mast cell granules. The mouse peritoneal mast cells were separated by glass adherence on cover glasses. The effect of incubation with increased doses of vitamin A, the effect of incubation with increased doses of human IgG (HIgG) followed by anti-human IgG (anti HIgG) and the combined effect of the lowest dose of vitamin A and the lowest dose of HIgG used, were investigated. The results are expressed as the percentage of mouse mast cells degranulated by treatment and indicate that degranulation increases in direct proportion with the vitamin A concentration and also in direct proportion with the HIgG concentration in the medium. When both are combined a degranulation percentage higher than the sum of each one separately, indicating that vitamin A produced a potentiation of most cell degranulation. These results are discussed in view of the fact that vitamin A alone induces mast cell degranulation and that there may be some clinical implications if the potentiating effect produced by vitamin A in the heterologous system described (mouse mast cells HIgG and anti HIgG) also occurs in the homologous system of anaphylaxis (homologous mast cells, IgE and anti IgE).