open access

https://hdl.handle.net/2115/63973

The effect of ovariectomy on urethral continence mechanisms during sneeze reflex in middle-aged versus young adult rats

英語

apoptosis

2016-01

Wiley-Blackwell

Neurourology and Urodynamics

35(1)

122-127

Aims: 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.

学術雑誌論文

Accepted Manuscript

This 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.

0733-2467

AA10631557