Inhibin is one of several hormones which collectively regulate the human female reproductive endocrine system. In recent years, physiologists have been able to separately assay two forms of inhibin. We begin by discussing the physiology and endocrinology that underlie the menstrual cycle. Then, we fit an existing delay differential equation model of the human menstrual cycle to new data describing average hormone levels of young women throughout the menstrual cycle. Next, we consider the existence and stability of equilibrium and periodic solutions, analyze bifurcations, and perform a sensitivity analysis. We compare and contrast these results to previously published results based on the same model but a different data set. Because the introduction of exogenous hormones, whether pharmacological or environmental, can have significant effects on the menstrual cycle, we model the effects of these external hormones. Next, we introduce an expanded model that more fully accounts for the actions of both forms of inhibin. We optimize the parameters to fit the data, then discuss the equilibrium and periodic solutions, bifurcations, and sensitivity for this new model and parameter set. Next, we use the model to consider the effects of exogenous pharmacological hormones. Finally, we discuss the effects on the menstrual cycle of age-related hormone production changes that occur during the peri-menopausal years. This leads to a second parameter set, with only a few variations from the first one, for which the model approximates the monthly hormonal fluctuations for a woman around age 40. In closing, we discuss future possibilities for this line of research.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-06102008-194807 |
| Date | 18 June 2008 |
| Creators | Pasteur, Roger Drew II |
| Contributors | James F. Selgrade, John E. Franke, Robert H. Martin, Ernest L. Stitzinger |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-06102008-194807/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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