OBJECTIVE: This study was undertaken to test the null hypothesis that the number of striated muscle fibers in the ventral wall of the female urethra remains constant with increasing age. STUDY DESIGN: The urethra and surrounding tissues from 25 female cadavers, mean age 52 years (+/-SD 18, range 15-80 years), were selected for this study. Each specimen was divided along the midsagittal plane, and a Masson trichrome histologic section was prepared. A systematic count of striated muscle fibers in the ventral wall was then obtained at each decile of urethral length. RESULTS: A decrease in the total number of fibers within the sampled area was found with increasing age. The mean of the total fibers across all urethrae was 17,423 (+/-SD 9,624, range 4,788-35,867). Over the life span, an average of 364 fibers (2%) were lost per year (95% CI 197-531; P <.001). Mean fiber density was 671 (+/- SD 296, range 228-1374) fibers/mm2 and decreased by 13 fibers/mm2 per year (95% CI 8-17; P <.001). The mean lesser fiber diameter was 24 microm and did not change significantly with age ( P =.3). CONCLUSIONS: The number and density of urethral striated muscle fibers decline with age.
OBJECTIVE: This study was undertaken to test the null hypothesis that the number of striated muscle fibers in the ventral wall of the female urethra remains constant with increasing age. STUDY DESIGN: The urethra and surrounding tissues from 25 female cadavers, mean age 52 years (+/-SD 18, range 15-80 years), were selected for this study. Each specimen was divided along the midsagittal plane, and a Masson trichrome histologic section was prepared. A systematic count of striated muscle fibers in the ventral wall was then obtained at each decile of urethral length. RESULTS: A decrease in the total number of fibers within the sampled area was found with increasing age. The mean of the total fibers across all urethrae was 17,423 (+/-SD 9,624, range 4,788-35,867). Over the life span, an average of 364 fibers (2%) were lost per year (95% CI 197-531; P <.001). Mean fiber density was 671 (+/- SD 296, range 228-1374) fibers/mm2 and decreased by 13 fibers/mm2 per year (95% CI 8-17; P <.001). The mean lesser fiber diameter was 24 microm and did not change significantly with age ( P =.3). CONCLUSIONS: The number and density of urethral striated muscle fibers decline with age.
Authors: Wolfgang H Umek; Rohna Kearney; Daniel M Morgan; James A Ashton-Miller; John O L DeLancey Journal: Obstet Gynecol Date: 2003-11 Impact factor: 7.661
Authors: Daniel M Morgan; Wolfgang Umek; Kenneth Guire; Helen K Morgan; Alice Garabrant; John O L DeLancey Journal: J Urol Date: 2009-05-17 Impact factor: 7.450