Histocytochemical studies on hematoporphyrin photoradiation effect on two enzymes of human liver cancer cells in nude mice

After inoculating a human hepatocellular carcinoma cell line SMMC-7721 into the Balb/c nude mice, enzymatic histochemical studies of the succinic dehydro-genase (the marker enzyme of mitochondrial endomembrane) and 5/-nucleotidase (the marker enzyme of cytoplasmic membrane) were immediately performed at 5, 30 min, 2, 8, 24 h after treatment with iv carcinophotorin 5 rog/kg plus general red light. The activities of the two enzymes were estimated semiquantitatively under the optic microscope as well as quantitatively by means of Leitz MPV- II type of micro-spectrophotometer. The results showed that the activities of the succinic dehydrogenase gradually decreased with the lapse of time from 5 min after treatment. The activities of the 5/-nucleotidase increased at 5 min after treatment. decreased with the lapse of time from 5 min after treatment. The above results suggest that the damage to enzymatic protein in cell biomembrane is one of the main photodynamic effects on killing human liver cancer cells in vivo.