Microsomal chemiluminescence of benzo[a]pyrene-7,8-dihydrodiol and its synthetic analogues trans- and cis-1-methoxyvinylpyrene.
The cis- and trans-methoxyvinylpyrene (MVP) analogues of benzo[a]pyrene-7,8-dihydrodiol (7,8-diol) produce specific microsomal chemiluminescence comparable to that produced from 7,8-diol in Aroclor-induced rat liver microsome preparations. The chemiluminescence quantum yields, emission spectra, and the concentration and the temporal kinetics of these three substrates have been examined. Radiolabelled 7,8-diol and t-MVP exhibit significant covalent binding (more than 14%) to microsomal protein when metabolized enzymatically. The extreme quenching of the dioxetane chemiluminescence by both microsomes and phosphatidylcholine, as a model phospholipid, implies that despite the low quantum yield (approx. 10(-8) photons per substrate molecule) for microsomal chemiluminescence of these substrates, a significant fraction of their microsomal oxygenations may proceed via a dioxetane pathway.
Thompson
A
A
Biggley
W H
WH
Posner
G H
GH
Lever
J R
JR
Seliger
H H
HH
D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology; D001580:Benzopyrenes / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004101:Dihydroxydihydrobenzopyrenes; D005609:Free Radicals; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D010713:Phosphatidylcholines; D011485:Protein Binding; D051381:Rats; D013057:Spectrum Analysis; D013482:Superoxide Dismutase / Q000378:metabolism
D001571:Benzoflavones; D001580:Benzopyrenes; D004101:Dihydroxydihydrobenzopyrenes; D005609:Free Radicals; D010713:Phosphatidylcholines; C017228:benzo(a)pyrene 7,8-dihydrodiol; C011512:alpha-naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D002374:Catalase; D013482:Superoxide Dismutase