The effects of polyhalogenated biphenyls on the metabolism of aflatoxin B₁.
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1982.
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| Subjects: | |
| Online Access: | Link to OAKTrust Copy Link to ProQuest Copy |
| Abstract: | A rapid method for the determination of aflatoxins was developed using high pressure liquid chromatography (HPLC) and a radial compression separation system. This HPLC method was used to study the effect of two industrial chemical mixtures: the polychlorinated biphenyls (PCB's) and polybrominated biphenyls (PBB's) on the in vitro metabolism of the mycotoxin aflatoxin B(,1) by rat liver microsomes and the in vivo secretion of the toxic metabolite aflatoxin M(,1) in the milk of rats. A standard solution of aflatoxin B(,1), B(,2), G(,1),G(,2), and M(,1) were analyzed at flow rates of 2.0 and 6.0 ml/min. Retention times, peak heights, and peak areas were reproducible over a 3-day period. At 6.0 ml/min there was an approximate 25% loss in sensitivity but a greater than 50% reduction in retention time. Separation of all the aflatoxins was excellent using a dual flow rate of 2.0 ml/min with a change to 8.0 ml/min at 15 min post-injection. Spiked samples of liver, serum, and urine showed good resolution of all aflatoxin peaks at the higher flow rates. Aflatoxin B(,1) was metabolized in an in vitro microsomal system using microsomes isolated from rats pretreated with various inducers. Inducers used were phenobarbital, 3-methyl cholanthrene, Aroclor 1254 (PCB) and FireMaster BP-6 (PBB). Aflatoxin B(,1) metabolism by hepatic microsomes from PBB and PCB treated rats resulted in 16- and 30- fold increases, respectively, in the rate of formation of aflatoxin M(,1) and a two-fold increase in aflatoxin Q(,1) formation. Lactating post-partum rats were pretreated with Aroclor 1254. Four days post PCB treatment the rats were dosed ip with radiolabeled aflatoxin B(,1) and milk samples collected. Studies in vivo clearly demonstrated enhanced secretion of aflatoxin M(,1) by female lactating rats with prior exposure to PCBs. The use of the radial compression separation system for aflatoxin analysis decreased the HPLC analysis time needed for this environmentally important mycotoxin. The in vitro and in vivo results indicate that a possible consequence of low level exposure to PCB's or PBB's may be to increase the levels of aflatoxin M(,1) released into the milk. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Food Science and Technology." |
| Physical Description: | xiii, 227 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 182-218). |