ABSTRACT Endometriosis, defined by ectopic growths of uterine tissue, is considered an enigma because it is unknown how or even if these abnormal growths contribute to the painful
conditions including dysmenorrhea, dyspareunia, and chronic pelvic pain that often accompany the disease. Many clinicians and biomedical scientists assume that the amount of ectopic growth
(cysts) predicts the presence or severity of pain symptoms, even though considerable evidence suggests that this assumption is unwarranted. Studies from our laboratory using a rat model of
surgically-induced endometriosis (ENDO) demonstrated for the first time that the cysts develop a sensory and sympathetic nerve supply. This discovery gave rise to the hypothesis that this
newly-sprouted innervation of the cysts is a significant contributor to the development (i.e., generation) and maintenance of painful symptoms. One of these common symptoms,
studied here, is vaginal hyperalgesia (often called dyspareunia in women). The purpose of this dissertation was to use a combination of immunohistochemical, physiological, and
behavioral methods to test various aspects of this hypothesis. In the first study, the developmental time course of cyst innervation (sensory and sympathetic) and ENDO-induced vaginal
hyperalgesia was examined over a 10 week period post-ENDO. It was found that rudimentary innervation appears within the cysts at 2 weeks post-ENDO, and becomes
active at 3 weeks post-ENDO. Between 4 and 5 weeks post-ENDO, vaginal hyperalgesia becomes significant, but is highly variable as the innervation increases and
approaches maturity. By 8 to 10 weeks post-ENDO the cyst innervation and hyperalgesia have both matured completely, plateaued and stabilized. Based on these findings, the developmental
timeline was divided into three phases: INITIAL (1-2 weeks post-ENDO), TRANSITIONAL (4-6 weeks post-ENDO), and ESTABLISHED (8-10 weeks post-ENDO). In each phase, characteristics of the cyst
innervation and vaginal hyperalgesia were found to be as follows: INITIAL, no innervation and no vaginal hyperalgesia; TRANSITIONAL, immature but
active innervation and significant but highly variable hyperalgesia; ESTABLISHED, mature innervation and stabilized hyperalgesia both of
which varied with the estrous cycle. Then, in each of the three phases, the contribution of the cysts (and their innervation) to ENDO-induced vaginal hyperalgesia was tested, by removing the
cysts and assessing the effect on the development and maintenance of the vaginal hyperalgesia. In the TRANSITIONAL phase, the relationship between the severity of ENDO-induced vaginal
hyperalgesia and the innervation of the cysts, eutopic uterus, and vaginal canal was also assessed. The effect of cyst removal on ENDO-induced vaginal hyperalgesia in the INITIAL phase
prevented the development of vaginal hyperalgesia. In the TRANSITIONAL phase, cyst removal did not significantly alleviate the vaginal
hyperalgesia developed prior to cyst-removal, but, prevented its future development. In the ESTABLISHED phase, cyst removal completely
alleviated the vaginal hyperalgesia. Further, in the TRANSITIONAL phase, innervation of the cysts (sensory and sympathetic) and innervation of the vaginal canal
(sympathetic only) significantly correlated with severity of ENDO-induced vaginal hyperalgesia. Overall, results from these studies strongly support the general hypothesis that the
innervation of the cysts contributes to ENDO-induced vaginal hyperalgesia. Specifically, the cyst innervation likely contributes to the development, severity, and maintenance of ENDO-vaginal
hyperalgesia. Importantly however, the varying effects of cyst removal suggest that mechanisms by which the innervation operates to contribute to the vaginal hyperalgesia change during its
progression through the three phases from peripheral sensitization to peripherally-independent then peripherally-dependent, hormonally-modulated central sensitization. Thus changes, which
emerge most clearly in the TRANSITIONAL phase, could help explain the poorly-understood, clinically-challenging issue on how pain transitions from an acute to a chronic problem, not only in
endometriosis but also in other chronic pain conditions. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2014. / October 21, 2014. / cyst, endometriosis, hyperalgesia, innervation, pain, sprouting / Includes bibliographical references. / Richard Hyson, Professor Directing Dissertation; David Kirby, University Representative; Karen Berkley, Committee Member; Mary Gerend, Committee Member;
Frank Johnson, Committee Member; Mohamed Kabbaj, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_252865 |
| Contributors | Mcallister, Stacy L. (authoraut), Hyson, Richard L. (professor directing dissertation), Kirby, David, 1944- (university representative), Berkley, Karen J. (committee member), Gerend, Mary A. (Mary Ann) (committee member), Johnson, Andrew (committee member), Kabbaj, Mohamed (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Psychology (degree granting department) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (111 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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