EFFECT OF CISPLATIN AND FK565 ON THE ACTIVATION OF TUMOR-ASSOCIATED AND BONE-MARROW-DERIVED MACROPHAGES BY DALTONS LYMPHOMA

The present investigations were undertaken to study the effect of Dalt on's lymphoma (DL) in situ on the functions of DL-associated macrophag es (DL-AM) and bone marrow-derived macrophages (BMDM) in C3H/He mice. DL-AM showed enhanced production of reactive nitrogen intermediates (R NI) and tumor necrosis factor (TNF) compared with normal peritoneal ma crophages (NMO). BMDM of DL mice also showed enhanced production of RN I compared with BMDM of normal mice. These observations suggest that t he presence of DL in situ creates an environment which favours the act ivation of both DL-AM and macrophage progenitors located at a distant site. The effect of in vivo administration of chemotherapeutic drugs c isplatin and FK565 on the activation of DL-AM by DL cells was also inv estigated. Both cisplatin and FK565 augmented RNI production of NMO bu t differed in their effect on DL-AM. The production of RNI by DL-AM of cisplatin-treated mice was inhibited, whereas in the FK565 group it w as up-regulated.