The requirement of serine esterase function in complement-dependent erythrophagocytosis.

The p-nitrophenyl ethyl phosphonate esters have been shown to inhibit complement-dependent erythrophagocytosis when exposed to guinea pig polymorphonuclear leukocytes prior to the initiation of phagocytosis. Inhibition of phagocytosis occurred in a manner characteristic of the well-defined capacity of phosphonate esters to inactivate serine esterases: inhibition was irreversible, dependent upon the temperature of reaction and pH of the reaction medium, and proportional to the concentration of inhibitor used and the duration of exposure between leukocytes and inhibitor. Phosphonate inhibition was further shown to be independent of any general cell damaging effects of the compounds used.

The influence of antibodies on immunologic responses. I. The effect on the response to particulate antigen in the rabbit.

The influence of antibody on antibody formation to particulate antigen was examined in the rabbit with special reference to the importance of immunoglobulin type, the amount and relative proportion of antigen and antibody involved, and the specificity of this influence. 19S as well as 7S antibody was shown to be an effective inhibitor of antibody formation, although there was some evidence that 7S antibody was the more efficient of the two in doing so. The inhibitory effect of antibody was found to be specific for homologous antigenic determinants.

Observations on the histamine forming capacity of mouse tissues and of its potentiation after adrenaline.

1. The histamine forming capacity (h.f.