Water-soluble C60 and macrophages:: Morphologic features of FC4S-treated peritoneal macrophages in vitro and in vivo -: A preliminary report

Morphologic investigation of water-soluble hexasulfonated C-60 (FC4S) effects on rat peritoneal macrophages in vitro and in vivo was conducted by transmission electron microscopy. In the case of in vitro studies, two groups of spontaneous peritoneal macrophages were separately cocultured with FC4S in a concentration of either 0, or 100 ng/ml for 24 h. The other two groups were cocultured with either FC4S (100 ng/ml) for 12 h, or Pseudomonas aeruginosa exotoxin A (ETA) 100 ng/ml for 24 h. The former 12 h FC4S-treated group was subsequently cultured with ETA; for an another 12 h. All these 4 groups 24 h of cocultured monolayer cells were fixed in glutaraldehyde 2.5%, post fixed in 1% OsO4 and processed for morphologic evaluation. The results revealed that the viability of FC4S-treated cells in a healthy state, containing numerous cytoplasmic electron-dense (ED) bodies. The origin and nature of these ED bodies were not known. Comparable observation was obtained with the FC4S-pretreated and ETA-treated the cells as viable and healthy, This suggested the existence of plausible antioxidative bio-reactions involving phagocytosed hexa(sulfobutyl)[60] fullerenes in cocultured macrophages. In the case of in vivo studies, the cells removed from rats that were ip injected with 60 mg/kg of FC4S were found to be typical active macrophages that bore numerous lysosomes and phagolysosomes in a variable degree of phagocytosing state. The presence of phagolysosomes were attributable to the FC4S exposure. The affected cells were diagnosed as "phagolysosomal macrophagopathy".