caa a22 4500 477081266 CHVBK 20180405111450.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF02723000 doi (NATIONALLICENCE)springer-10.1007/BF02723000 Photodynamic effects of protoporphyrin on the cellular level—An in vitro approach [Elektronische Daten] [M. van Graft, J. Boot] Summary: The purpose of this study was characterizing the phototoxic action of protoporphyrin and cellular protection mechanisms, as studied on the cellular level. In this process, active oxygen is involved. As a biological system, rat hepatocyte shortterm and primary cultures were used. Phototoxicity of protoporphyrin could be observed, after previous absorption of protoporphyrin to membrane structures. Damaging of several cell organelles occurred, such as mitochondria and lysosomes. Peroxisomes were not affected. Coated vesicles located at the periphery of the cells' interior suggested that protoporphyrin absorption is mediated by an active uptake (endocytosis), as well as passive diffusion. Lipid peroxidation played a role in protoporphyrin photoxicity. Cellular protection mechanisms such as superoxide dismutase and the scavenger glutathione (GSH) protected the cells from active oxygen toxicity. In conclusion, protoporphyrin entered the cells by diffusion and endocytosis. Previous adsorption to the membrane structures was necessary for the expression of protoporphyrin phototoxicity. However, active oxygen itself could not be demonstrated. Lipid peroxidation was involved in cell-damaging processes. Mechanisms of protoporphyrin phototoxicity on the cellular level were studied. Rat hepatocyte primary and short-term cultures proved to be suitablein vitro systems for studying biochemical and morphological effects on the cellular level. Society for In Vitro Biology, 1996 cell culture systems nationallicence phototoxicity nationallicence protoporphyrin nationallicence hepatotoxicity nationallicence in vitro toxicology nationallicence scavengers nationallicence van Graft M. P. O. Box 85.284, 3508 AG, Utrecht, The Netherlands aut Boot J. P. O. Box 85.284, 3508 AG, Utrecht, The Netherlands aut In Vitro Cellular & Developmental Biology - Animal Springer-Verlag 32/7(1996-07-01), 394-398 1071-2690 32:7<394 1996 32 11626 https://doi.org/10.1007/BF02723000 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02723000 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- van Graft M. P. O. Box 85.284, 3508 AG, Utrecht, The Netherlands aut NATIONALLICENCE 700 1- Boot J. P. O. Box 85.284, 3508 AG, Utrecht, The Netherlands aut NATIONALLICENCE 773 0- In Vitro Cellular & Developmental Biology - Animal Springer-Verlag 32/7(1996-07-01), 394-398 1071-2690 32:7<394 1996 32 11626 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer