title: Formation of metal complexes of tumor-localizing porphyrins.
abstract: Whereas the tumor localizer and photosensitizer hematoporphyrin derivative (Hpd) has its fluorescence emission maximum at 610-630 nm, several authors have reported that in aqueous solutions of hematoporphyrin (Hp) and Hpd, or in tumors after an injection of Hpd, a compound is formed which has its fluorescence emission maximum at 570-590 nm. This work (HPLC and fluorescence analysis) indicates that this peak is due to the formation of Zn-porphyrins either in vitro or in vivo. Cu- and Co-porphyrins may be formed as well, from traces of these metallic ions. In contrast to free porphyrins and Zn-porphyrins the latter complexes are non-fluorescent and do not act as photosensitizers.
mesh_terms: D000818:Animals; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D003035:Cobalt / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D017324:Hematoporphyrin Derivative; D006415:Hematoporphyrins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000378:metabolism*; D011838:Radiation-Sensitizing Agents; D013050:Spectrometry, Fluorescence; D015032:Zinc / Q000378:metabolism*
chemical_list: D006415:Hematoporphyrins; D011838:Radiation-Sensitizing Agents; D003035:Cobalt; D017324:Hematoporphyrin Derivative; D003300:Copper; D015032:Zinc