Abstract
Purpose:
The objective of this study was to evaluate whether the effect on afferent c-fiber activity is the underlying mechanism of intravesical electrical stimulation (IVES) in spinal cord injured rats.
Materials and Methods:
Thirty five female Sprague-Dawley rats weighting 200-300g each were divided into the normal and spinalized groups. For the spinalized rats, we observed the c-fos expression, and we compared this in the non-IVES group with that in the IVES group. Cystometrograms were performed for all the groups via a suprapubic catheter.
Results:
After performing IVES in the normal and spinalized rats, the abnormal increases of the intercontraction interval (ICI) and the voiding pressure (VP) were reduced close to the normal range. In the spinalized rats, the number of c-fos positive cells in the dorsal commissure (DCM) decreased in the group that had IVES performed when compared with the non-IVES group.
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![]() | Fig. 1.Effects of intravesical electrical stimulation. Cystometro- gram after the intravesical instillation of saline in the normal group (A) and the spinalized group (B). Intravesical electrical stimulation improved the urodynamic parameters in the spinalized group (C). Note the decrease in the number and the pressure of the nonvoiding contractions. ∗: voiding contraction (VC), : nonvoiding contraction (NVC). |
![]() | Fig. 2.Intravesical electrical stimulation decreased the intercontraction interval and voiding pressure in the spinalized group (A, B). The number and pressure of the nonvoiding contractions decreased after intravesical electrical stimulation (C, D). SCI: spinal cord injury, IVES: intravesical electrical stimulation. ∗: statistical analysis by Student's t-test (unpaired) (p<0.05). |
![]() | Fig. 3.Immunohistochemical staining. The normal group (A), the saline group (SCI+NS) (B), and the IVES groups (SCI+IVES) (C). SCI: spinal cord injury, NS: normal saline, IVES: intravesical electrical stimulation. |
![]() | Fig. 4.Topographical distribution according to the c-fos expression in the L6-S1 spinal cord of the spinalized rat. Saline group (□) and capsaicin group (□) (A), saline group (□) and IVES group (■) (B). SPN: sacral parasympathetic nucleus, DCM: dorsal commissure, MDH: medial dorsal horn, LDH: lateral dorsal horn. |
Table 1.
The number of Fos immunoreactive (IR) cells induced in each group (means 土 SE)
∗ : p-value indicates the comparison beween saline group (SCI+NS) and capsaicin group (SCI+Caps) (p<0.05)
† : p-value indicates the comparison between saline group (SCI+NS) and IVES group (SCI+IVES)(p<0.05), SCI: spinal cord injury, NS: normal saline, Caps: capsai in, IVES: intravesical electrical stimulation, MDH: medial dorsal horn, LDH: lateral dorsal horn, DCM: dorsal commissure, SPN: sacral parasympathetic nucleus