Comparison of the effects of human pregnancy serum and anti-inflammatory compounds on the release of lysosomal enzymes from macrophages.

Human sera and anti-inflammatory drugs were compared for their ability to inhibit the zymosan-induced release of beta-glucuronidase from cultured rat peritoneal macrophages. Late pregnancy serum was the most potent in this respect and produced a dose-related suppression with a maximum of 94% when 15% (v/v) serum was incorporated into the culture medium. The effect was not shown by male serum and was associated with compounds of low molecular weight. However, steroids, commonly elevated in level during pregnancy, did not appear to be responsible for the inhibition of enzyme release.