title: [Effect of hematoporphyrin derivative (HpD) on nucleoside transport and nucleoside kinase activity of cancer cells].
abstract: The HpD and dihematoporphyrin ethers (Photofrin II) at the dose of 5 micrograms/ml significantly inhibited the transport and uptake of thymidine and uridine in Ehrlich ascites carcinoma (EAC) cells. The 50% inhibiting doses (ID50) of HpD and Photofrin II II for thymidine uptake were 1.0 microgram/ml and 7.0 micrograms/ml, and for uridine were 1.2 micrograms/ml and 1.6 micrograms/ml, respectively. The uptake kinetics were greatly changed. The Km values were increased and the Vmax values decreased. The incorporation of 3H-TdR and 3H-UR into the acid-soluble and insoluble materials of EAC cells was depressed. HpD at the dose of 10 micrograms/ml did not influence the activity of thymidine kinase but the uridine kinase activity was mildly inhibited. These results show that the cell membrane may be the initial acting site by both drugs.
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism* / Q000648:ultrastructure; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D005260:Female; D017324:Hematoporphyrin Derivative; D006414:Hematoporphyrin Photoradiation; D006415:Hematoporphyrins / Q000494:pharmacology*; D051379:Mice; D009705:Nucleosides / Q000378:metabolism*; D010778:Photochemotherapy; D013937:Thymidine Kinase / Q000378:metabolism; D014541:Uridine Kinase / Q000378:metabolism
chemical_list: D006415:Hematoporphyrins; D009705:Nucleosides; D017324:Hematoporphyrin Derivative; D013937:Thymidine Kinase; D014541:Uridine Kinase