Circulating sex hormone levels in rats: a systematic analysis of the literature and perinatal BPA study

In the study of reproductive toxicology, animal models play an important role in elucidating the mechanisms by which a toxicant exerts its deleterious effects, as well as serving as a translational system for comparison to human biology. The anatomy, physiology, and molecular mechanisms of the reproductive system of these models should first be well characterized within the species prior to making inter-species predictions on the toxicant's effects. Here we conducted a systematic analysis of the available literature to characterize within the rat model how three different, popular outbred strains (Wistar, Sprague-Dawley, and Long-Evans) may each possess distinct levels of basal peripheral testosterone (T), estradiol (E2), or progesterone (P4) levels, according to rat sex and age. We found that estradiol and testosterone, but not progesterone, were different depending on rat strain, which could possibly point to inherent differences in the hormonal regulatory systems between strains, and also potential differences between strains in susceptibility to the detrimental effects of reproductive toxicants. As an extension of this analysis of the factors that influence sex hormones, we also examined the effect of the known endocrine disrupting chemical, bisphenol-A (BPA), at environmentally relevant ranges on the sex hormones, follicle-stimulating hormone (FSH), luteinizing hormone (LH), T, E2, and P4 in perinatally exposed, infantile rats. We found no effect of BPA on sex hormone levels in these rats, which is in both concordance and opposition to other studies that have examined this developmental time point. The current contradictory nature of the literature regarding the effect of environmentally relevant dosages of BPA could benefit from an examination of the factors other than toxicant exposure leading to the different results.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

VMS - Comparative Biosciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Meisner, Eleanor Frances

Contributors dc:contributor

• Lavergne, Sidonie N.
• Flaws, Jodi A.
• Mahoney, Megan

• comparative biology
• animal models
• rat models
• rats
• outbred strain
• strain differences
• genetic differences
• Sprague-Dawley
• Wistar
• Long-Evans
• reproductive toxicology
• systematic analysis
• literature review
• basal levels
• sex hormone
• sex steroid
• testosterone
• estradiol
• progesterone
• bisphenol-a
• BPA

Statement dc:rights

• Copyright 2016 Eleanor Meisner

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/92718

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/92718