Use this URL to cite or link to this record in EThOS:
Title: Xenoestrogens : assessing the predictability of mixture effects
Author: Payne, Joachim Peter
ISNI:       0000 0001 3479 7829
Awarding Body: University of London
Current Institution: University College London (University of London)
Date of Award: 2001
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Recently there has been growing concern over the increasing incidence of endocrine related disorders in both humans and wildlife. This has prompted researchers to speculate about a common underlying environmental cause. A large number of natural and synthetic chemicals have been shown to interact with the estrogen receptor, and it is believed that these xenoestrogens are the agents responsible. We are constantly exposed to many such agents, however, the study of interactions between these chemicals within biological systems has often been hampered by the application of unsuitable models of mixture action. In this study we have employed, for the first time, the well-validated models of concentration addition and independent action to analyse xenoestrogen mixture effects in the MCF-7 cell proliferation assay and the yeast estrogen screen. Both models yield excellent predictions of mixture action in our test systems, and indicate that the xenoestrogens o,p'-DDT, p,p'-DDT, p,p'-DDE and β3-HCH act additively in the MCF-7 assay. Similarly, we observe that interactions between o,p'-DDT, 4-octylphenol, 4-nonylphenol and genistein are additive in the yeast estrogen screen. Assuming that additivity holds true in vivo, we have attempted to estimate the human exposure to xenoestrogens which would be required to significantly modulate the activity of estradiol. Our calculations indicate that at current levels of exposure these chemicals could pose a risk to human health. Although this estimate is by no means conclusive, we feel that a large step forward has been made in understanding xenoestrogen mixture effects.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Pharmacology & pharmacy & pharmaceutical chemistry