A Comparison of Mast‐Cell Reactions in the Rat, Hamster and Guinea Pig

Parallel in vitro experiments on the mesenterial mast cells were carried out in the rat, hamster and guinea pig. Incubation of mesentery in small, rising concentrations (0.1–100 μg/ml) of compound 48/80, lecithinase A and decylamine caused proportional degrees of “disruption” of the rat and hamster mast cells. pH curves and experiments with enzyme inhibitors gave the same results in the rat and hamster and suggested that, in these two species, the disruption caused by compound 48/80 and lecithinase A involves a similar, enzymatic mechanism, whereas the effect of decylamine is non‐enzymatic. The guinea‐pig mast cells reacted with dissolution and disappearance (but not with the uniform disruption seen in the rat and hamster) upon incubation with decylamine and lecithinase A. However, high doses and a prolonged incubation time was needed for maximal effect and enzyme inhibitors could not block it. It is concluded that the effects on guinea‐pig mast cells was a non‐enzymatic lysis of the cell membrane. Compound 48/80 was without effect on the mast cells of the guinea‐pig. The resistance to hypotonic solutions was about the same in all three species but the “disruption” of the rat and hamster mast cells occurred much faster than the “disappearance” of guinea‐pig mast cells. Provided a sufficient reaction time is allowed, this “disappearance” reaction is the best way of evaluating mast‐cell reactions in the guinea pig.