Chromosomal damage to preimplantation mouse embryos in vitro by naphthalene and aflatoxin B₁ /
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| Other Authors: | , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | The developmental toxicity and clastogenicity of naphthalene (NAP) and aflatoxin B1 (AFB1) have been compared within an in vitro preimplantation mouse embryo culture system. Whole mouse embryos were collected 72 hr. after conception and co-cultured in serum-supplemented NCTC 109 medium containing concentrations of NAP of 0.08mM, 0.12mM, 0.16mM and 0.24mM. Concentrations of media in which embryos were exposed to AFB1 included 1uM, 5uM, 10uM, 20uM and 100uM. The embryos were exposed to the respective dose in media for one hour, then transferred to untreated media and cultured for 24 hr. Embryos were harvested, metaphase spreads prepared, and chromosomal aberrations analyzed as a function of dosage. Concurrently, embryos were harvested and metaphase spreads prepared after 1 hour, 24, 48 and 72 hr. in culture. It was found that in the presence of rodent hepatic S-9 fractions, both NAP and AFB1 were metabolically bioactivated to induce significant frequencies of aberrations. This was also found to be true in those treatments without S-9 fractions added, although the frequency of chromosomal damage was not as great. Further, NAP and AFB1 clastogenicity markedly decreased after 72 hr., implicating the involvement of embryonic DNA repair. These findings suggest that NAP and AFB1 are clastogenic in the absence of S-9 (exogenous biotransformation). Further, these observations indirectly indicate the presence of embryonic enzyme activity competent to metabollically bioactivate NAP and AFB1. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Veterinary anatomy." |
| Physical Description: | xii, 174 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |