Suppressive effect of 3-methylcholanthrene on phagocytic activity of mouse peritoneal macrophages for Torulopsis glabrata.

The effect of 3-methylcholanthrene (MCA) on the phagocytic activity of mouse peritoneal macrophages for Torulopsis glabrata was investigated. Macrophages were maintained in glass scintillation vials or on cover slips in Leighton tubes with the use of Hanks' balanced salt solution plus 30% horse serum. Graded amounts of MCA were incorporated into the medium and the macrophages were parasitized with viable cells of T. glabrata. Macrophages from C3H mice, a strain highly susceptible to MCA carcinogenesis, were more prone to the suppressive effect of MCA than were the macrophages from CFW mice, a relatively resistant strain. Significant suppressive effect on phagocytosis of macrophages from C3H mice was observed with 5 micrograms MCA/ml, whereas up to 50 micrograms MCA/ml did not alter the phagocytic activity of CFW macrophages. However, 100 micrograms MCA/ml also suppressed the phagocytosis of CFW macrophages. Suppression in phagocytosis of C3H macrophages was observed after 6 hours' exposure to MCA, whereas a similar effect on CFW macrophages was seen after 12 hours. Treatment with 100 micrograms MCA/ml imparied the fungicidal activity of both C3H and CFW macrophages. These results indicate a correlation between the suppressive effect of MCA on macrophage activity and the strain susceptibility of mice to chemical carcinogenesis.