Effect of proteinases on EA (IgG)-binding receptors of rat macrophages.

Pronase, trypsin and delta-chymotrypsin deplete rat alveolar peritoneal macrophages of EA (IgG)-binding activity. Trypsin and delta-chymotrypsin show an initially--under certain conditions and lasting--enhancement of receptor activity. Cycloheximide, an inhibitor of protein biosynthesis, accelerated the loss of Fc-receptors and inhibited their reappearance. There are differences between alveolar and peritoneal macrophages in the rate of loss as well as of regeneration of Fc-receptors.