This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Baird, W. M. Articles by Diamond, L. Search for Related Content PubMed PubMed Citation Articles by Baird, W. M. Articles by Diamond, L.

Formation of Benzo(a)pyrene-Glucuronic Acid Conjugates in Hamster Embryo Cell Cultures¹

The Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania 19104

Secondary cultures of hamster embryo cells exposed to 0.5 nmole [³H]benzo(a)pyrene (BP) per ml medium metabolized more than 80% of the [³H]BP within 24 hr, and 90% of the metabolites formed remained in the aqueous phase when the medium was extracted with an organic solvent. Thin-layer chromatography of the water-soluble material showed that it contained several minor product peaks and one major product that was sensitive to ß-glucuronidase treatment and cochromatographed with a marker of a BP phenol-glucuronide in three thin-layer chromatography systems.

ß-Glucuronidase treatment of the aqueous phase of a sample of organic solvent-extracted medium from hamster embryo cell cultures converted at least 40% of the material to organic solvent-soluble derivatives. The released material contained 33 to 40% 9-hydroxybenzo(a)pyrene, 18 to 21% 3-hydroxybenzo(a)pyrene, and 8 to 11% BP quinones. Similar amounts of BP phenols and BP quinones were obtained by treating medium samples directly with ß-glucuronidase. In contrast, the BP metabolites in the organic solvent extract of the original medium were mainly BP dihydrodiols.

Cells exposed to 3-hydroxybenzo(a)pyrene formed a water-soluble product with chromatographic behavior and fluorescence spectra identical with those of 3-hydroxybenzo(a)pyrene glucuronide. Cells exposed to 0.5 nmole [³H]-9-hydroxybenzo(a)pyrene per ml medium converted more than 90% of this phenol to water-soluble derivatives within 24 hr; more than 80% of these were converted to [³H]-9-hydroxybenzo(a)pyrene by ß-glucuronidase treatment.

These results demonstrate that formation of glucuronic acid conjugates of BP phenols is a major pathway of BP metabolism in hamster embryo cells in culture and that ß-glucuronidase treatment of culture medium from these cells provides a method for determining the sites of oxidation of more than one-third of the total BP metabolites formed.

¹ This investigation was supported in part by Grants CA-19948, CA-08936, CA-10815, and CA-16685 and Contract NO1-CP-55655 from the National Cancer Institute and by Grant RR-05540 from the Division of Research Resources.

² To whom requests for reprints should be addressed.

Received 3/23/77. Accepted 5/26/77.