Effect of fibroblast interferon and recombinant gamma interferon on zymosan-induced nitroblue tetrazolium reduction in mouse peritoneal macrophages.

Mouse peritoneal macrophages (MPM) were cultivated with a fibroblast interferon (IFN) preparation or recombinant gamma-IFN (rIFN-alpha) for 1, 24 or 48 h. The zymosan-induced reduction of nitroblue tetrazolium (NBT) in these MPM was then measured. Fibroblast IFN enhanced the NBT reducing capacity of MPM when the incubation period was 1 h. When the incubation period was extended to 48 h, a suppressed NBT reduction by fibroblast IFN treated MPM was recorded. The influence of rIFN-alpha on MPM with regard to NBT reduction was minor. Only when the MPM were treated with a moderate dose of rIFN-alpha (10 U/ml) for 48 h was an enhanced NBT reduction recorded.