Item – Theses Canada

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OCLC number
57167783
Link(s) to full text
LAC copy
LAC copy
Author
Armstrong, Stephen James,1976-
Title
Effects of estrogen replacement and chronic PGHS-2 inhibition on vascular function in the aged rat.
Degree
M. Sc. -- University of Alberta, 2003
Publisher
Ottawa : National Library of Canada = Bibliothèque nationale du Canada, [2004]
Description
2 microfiches.
Notes
Includes bibliographical references.
Abstract
Aging and estrogen deficiency contribute to vascular dysfunction. Young ovariectomized rats have increased prostaglandin H synthase (PGHS)-dependent vasoconstriction that can be prevented with estrogen. PGHS-2-dependent vasoconstriction predominates in aging rats. Hypothesis (I) Estrogen suppresses PGHS-2-dependent constriction in aged rats, (II) Chronic PGHS-2 inhibition reduces PGHS-dependent vasoconstriction in aging. Ovariectomized, aged rats given (I) placebo or estrogen-treatment or (II) placebo or the PGHS-2 inhibitor for one or four weeks, had their mesenteric arteries assessed for endothelium-dependent relaxation in the absence/presence of PGHS inhibitors. (I) PGHS-2 inhibition increased vasorelaxation to a greater extent than PGHS-I inhibition. Estrogen prevented PGHS-dependent constriction with an associated reduction in PGHS-2 expression. (II) One week of PGHS-2 inhibition abolished a PGHS-dependent shift in relaxation while four weeks enhanced PGHS-dependent modulation of vasoconstriction. PGHS-2 expression increased with prolonged PGHS-2 inhibition, corroborating the paradoxical increase in PGHS-dependent vasoconstriction. Estrogen, but not chronic PGHS-2 inhibition may counteract aging vascular effects.
ISBN
0612877124
9780612877122