Erectile dysfunction and cardiovascular disease share etiologies, and commonly
coexist. One unifying concept is that the arterial insufficiency in hypertension is also the
primary basis for blunted sexual responses. The objective of these studies was to
characterize the age-related changes in the structure and function of the pudendal artery
(the main resistance vessel) in young and old normotensive and hypertensive animals in
relation to erectile function. In addition, we assessed the impact of antihypertensive
treatments and lifestyle modifications, such as exercise and/or caloric restriction, on
erectile responses and the structure and function of the pudendal artery.
In 30 week old hypertensive rats or following re-challenges at 50 and 70 weeks,
antihypertensive treatment (enalapril or hydralazine) did not prevent the age-related
decline in erectile function. Experiments involving cross-over kidney transplantations
between treated and untreated young hypertensive rats revealed that changes in penile
vasculature and not the level of arterial pressure were important for normalizing erectile
responses. In addition, intervention with exercise and caloric restriction showed that
these treatments substantially improved erectile responses in normotensive and
hypertensive rats.
The pudendal artery in young normotensive rats was found to have a thick medial
layer but a relatively small lumen. With age, the pudendal lumen didn’t change, but all
components of the medial layer were markedly increased. Of interest, the smooth muscle
cells within the pudendal medial layer became more disorganized with aging, although
iii
contractions were similar. In contrast, endothelium-dependent relaxation decreased with
age.
Young hypertensive rats also had an increased wall thickness, but not lumen
diameter or extracellular matrix. Antihypertensive therapy significantly decreased the
pudendal wall thickness. In aging hypertensive rats, the pudendal artery walls were even
thicker, lumen decreased and extracellular matrix greatly enhanced compared to younger
rats. In addition, there were numerous regions of intimal thickening associated with
marked disruptions of the internal elastic lamina. Moreover, pudendal smooth muscle
cells bordering the intima and in the neointima were round in shape, and electron
microscopy confirmed their synthetic state.
Taken together, these findings provide key evidence of the importance of the
structure and function of the pudendal artery in facilitating erectile responses. / Thesis (Ph.D, Pharmacology & Toxicology) -- Queen's University, 2009-05-19 12:55:30.469
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/1881 |
| Date | 19 May 2009 |
| Creators | Hannan, JOHANNA |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 6116823 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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