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THE EFFECT OF PROTOPORPHYRIN ON HISTAMINE SECRETION BY RAT PERITONEAL MAST CELLS: A DUAL PHOTOTOXIC REACTION
Author(s) -
Ortner Mary J.,
Abhold Raymond H.,
Chignell Colin F.
Publication year - 1981
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1981.tb05429.x
Subject(s) - phototoxicity , lysis , protoporphyrin , histamine , chemistry , mast cell , secretion , biophysics , cell , microbiology and biotechnology , biochemistry , pharmacology , immunology , in vitro , biology , porphyrin
— Protoporphyrin‐induced phototoxicity in rat peritoneal mast cells was manifested either by inhibition of 48/80‐stimulated histamine secretion or by cell lysis. At a protoporphyrin concentration of 100ng/m/ (0.17 μM), histamine secretion was completely inhibited after 30min illumination. After initiation, the inhibited state progressed in the dark, and was irreversible, however, it did not develop into cell lysis. More severe phototoxic reactions in mast cells could not be produced by increasing the PP concentration or the incubation time; however, cell lysis was evoked by increasing the light intensity between 180–950W/m 2 , using a light source with emission maxima in the 350–470nm region. Dual phototoxic effects could also be demonstrated in erythrocytes by manipulating the illumination conditions. Increased resistance to osmotic lysis was seen under moderate conditions, and decreased resistance and cell lysis were seen under severe conditions. In the absence of protoporphyrin, the effect of light alone on mast cells was similar to protoporphyrin‐phototoxicity, although the light intensities required were higher both for inhibition (60–130W/m 2 ) and lysis (280–950W/m 2 ). The data therefore indicate that certain cell functions can be specifically disrupted by phototoxic reactions that are not cytotoxic; however, phototoxic reactions that lead to severe membrane protein denaturation and cell lysis also occur. The manifestation of these dual effects depends on the intensity of illumination in the 350–470nm region.