The effect of ovariectomy on biomarkers of urogenital ageing in old versus young adult rats.

The aim of this study was to compare the effects of ageing and ovariectomy on biomarkers of urogenital ageing in old and young-adult rats. Fisher 344 rats (18- and 3-months-old, n = 6 x 2) underwent ovariectomy. Age-matched sham animals received no intervention (n = 6 x 2). One month later, biomarkers of urogenital ageing were evaluated (light microscopic count of urethral and anal canal submucosal blood vessels, Western blot analysis of urethral, and anal canal submucosal collagen I and III and cytoplasmic p27(kip1) expression in the striated urethral and anal sphincters and levator ani and gel electrophoresis of isomyosin I proportion in these muscles) and compared in all groups (n = 24). All biomarkers of urogenital ageing studied were significantly increased in old compared to young-adult sham rats. Ovariectomy significantly increased these changes further in old versus young-adult rats with either smaller or larger differential effect than ageing compared to young-adult sham animals. Ovariectomy significantly exacerbates normative urogenital ageing changes in rats.