title: Transfer of protoporphyrin IX between cells.
abstract: Human adenocarcinoma cells of the line WiDr and human leukemia T cells of the line Jurkat were incubated with 5-aminolevulinic acid and found to produce protoporphyrin IX (PpIX). They were able to transfer a fraction of the sensitizer to neighboring control cells. The transfer took place through direct membrane contact. Light exposures, inactivating about 20% of the sensitized cells, did not result in any acceleration of the transfer of PpIX. This is in contrast to what has been reported for PpIX in erythrocytes from patients with erythropoietic protoporphyria. In these cells light exposure transfers PpIX from the binding sites on hemoglobin to the plasma membrane and further to neighboring cells. The lack of light-induced transfer in the WiDr and Jurkat cells may be related to the binding sites of PpIX, supposedly membrane lipids and proteins embedded therein. Light exposure slightly increased the rate of loss of PpIX from WiDr cells.
authors.affiliation: Department of Biophysics, The Norwegian Radium Hospital, Oslo, Norway. johan.moan@labmed.uio.no
authors.forename: Johan
authors.initials: J
authors.lastname: Moan
authors.forename: Li Wei
authors.initials: LW
authors.lastname: Ma
authors.forename: Trond
authors.initials: T
authors.lastname: Stokke
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000622:Aminolevulinic Acid / Q000494:pharmacology*; D002450:Cell Communication / Q000187:drug effects*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D007938:Leukemia / Q000378:metabolism; D008027:Light; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000378:metabolism / Q000494:pharmacology*; D011524:Protoporphyrins / Q000096:biosynthesis / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX