2024-03-29T09:18:43Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/639732022-11-17T02:08:08Zhdl_2115_20043hdl_2115_137The effect of ovariectomy on urethral continence mechanisms during sneeze reflex in middle-aged versus young adult ratsKitta, TakeyaYoshikawa, SatoruKawamorita, Naokide Groat, William C.Nonomura, KatsuyaYoshimura, Naokistress urinary incontinenceovariectomysneezeratapoptosis490Aims: Stress urinary incontinence (SUI) is common in post-menopausal women. The present study therefore examined how aging and estrogen deficiency induced by ovariectomy (OVX) affect the urethral continence mechanism that prevents sneeze-induced SUI in rats. Methods: Young (3 months old) and middle-aged (12 months old) female rats underwent bilateral OVX or sham operation. Urethral activity was measured by the amplitude of urethral responses during sneezing (A-URS) and urethral baseline pressure (UBP). Apoptotic changes in urethral tissue sections were examined by the TUNEL method. Results: In middle-aged rats, UBP, but not A-URS, was significantly decreased compared to young rats. In 3-week OVX rats, A-URS was significantly decreased compared to sham rats in both young and middle-aged groups, and the OVX-induced reduction in A-URS was more pronounced in middle-aged rats. Neither young 3-week OVX nor sham rats leaked during sneezing; however, SUI occurred in 2/8 middle-aged rats with 3-week OVX, and after 6 weeks of OVX, SUI was observed in 5/8 young rats and 6/8 middle-aged rats. In middle-aged rats, TUNEL positive cells were significantly increased in urethral striated muscles whereas, after OVX, the increased number of positive cells was also found in the mucosa. Conclusions: These results indicate that aging is more likely to impair baseline urethral function than striated muscle-mediated reflex activity although apoptotic changes are found in urethral striated muscle. Estrogen deficiency additionally impairs the striated muscle-mediated continence reflex. Thus, aging and estrogen deficiency differently and additively affect baseline urethral function and neurally-evoked, striated muscle-mediated urethral continence mechanisms to induce SUI.Wiley-BlackwellJournal Articleapplication/pdfhttp://hdl.handle.net/2115/63973https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/63973/1/NeurourolUrodyn35_122.pdf0733-2467AA10631557Neurourology and Urodynamics3511221272016-01enginfo:pmid/25358967info:doi/10.1002/nau.22690This is the peer reviewed version of the following article: Neurourology and Urodynamics, Volume 35, Issue 1, pages 122–127, 2016, which has been published in final form at http://dx.doi.org/10.1002/nau.22690. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.author