Effects of Injection Therapy using Muscle Derived Stem Cell/ Chitosan/ Hydroapatite Composite Gel in a Rat Model of Urinary Incontinence

Abstract

Purpose: We investigated whether periurethral injections of musclederived stem cells (MDSC) and chitosan/hydroapatite after denervation of rat's pudendal nerve could increase the leak point pressure over a long time period in a rat model of urinary incontinence. Materials and Methods: Muscle-derived stem cells isolated from the gastrocnemius muscle of normal female rats were purified to obtain a myogenic population by using the preplate technique. The N group was the normal female rats, the D Group was the pudendal nerve transected group and the M Group was the MDSC/chitosan/hydroapatite composite gel injected group after pudendal nerve transection. The MDSC/chitosan/hydroapatite composite gel was injected into the proximal periurethral area. At 2 and 4 weeks, visually identified leak point pressure measurement was done with using the vertical tilt/intravesical pressure clamp model of urinary incontinence. The rats were then sacrificed and the periurethral tissues harvested for histological examination. Results: The leak point pressure was significantly lower in the D group at each time compared with the N group, and the leak point pressure in the N and M groups were significantly higher than those in the D group at both 2 and 4 weeks. The persistence of MDSC over the period of study was verified by histological examination. Conclusions: MDSC/chitosan/hydroapatite injection into the denervated external urethral sphincter in female rats increased the leak point pressure at 2 and 4 weeks. This MDSC/chitosan/hydroapatite composite gel can be an alternative injection method for treating urinary incontinence in the future. (Korean J Urol 2007;48:627-632) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏