DIFFERENTIAL EFFECT OF HOG GASTRIC MUCIN ON PROPERDIN AND HOST RESISTANCE TO INFECTION

Abstract

Various commercial lots of hog gastric mucin are shown to vary widely in their ability to decrease the natural resistance of mice to experimental infection with either Escherichia coli or Staphylococcus aureus when given intra-peritoneally at 25 mg/mouse. Similar variations are also reported in their ability to destroy properdin in vitro and their is an apparent correlation of these 2 effects. Injection of as little as 5 mg of any mucin sample, however, uniformly reduces serum properdin levels to zero in 6 hours with a return to normal at 72 hours. Furthermore, all samples are shown to enhance host resistance by 2-4 fold upon injection of 0.5 mg prior to infection. It is concluded that hog gastric mucin has an antiproperdin activity similar to that of the bacterial and tissue polysaccharides but that this is not the primary factor in its ability to reduce host resistance to infection.