ULTRASTRUCTURAL CHANGES OF THE NEURONAL COMPONENT IN THE DETRUSOR MUSCLE FOLLOWING SACRAL ROOT STIMULATION OF DECENTRALIZED DOGS

Abstract

Objectives

To study ultrastructural changes in the neuronal component of the detrusor muscle during the spinal shock phase and following early electric neurostimulation in an animal model.

Material and Methods

12 dogs were decentralized at the levels from S1 to S3, while three animals were provided as normal controls. The decentralized animals were divided into four groups according to the method of bladder voiding: Group 1A: intermittent catheterization without neurostimulation, Group 1B: intermittent catheterization followed by neurostimulation, Group 2A: early prolonged neurostimulation and Group 2B: early neurostimulation followed by intermittent catheterization. From the different groups, bladder tissue blocks were dissected, fixed in glutaraldehyde and processed for electron microscopic study.

Results

Early prolonged sacral root neurostimulation demonstrated a significant reduction of degenerated axons (mean = 28.9% ± 1.7), an increased frequency of cholinergic axons (mean = 16% ± 0.75) and an exhibited significant narrowing of the neuroeffector gap junctions (mean = 117.25 ± 22.6 nm) in comparison to non-stimulated animals (mean values were 80.5% ± 0.75, 5.4% ± 1.7, and 281 ± 62.6 nm, respectively) which were voided with intermittent catheterization. However, early sacral root stimulation followed by intermittent catheterization displayed a significant reduction of axonal degeneration (mean = 48.3% ± 1.8) in comparison to late stimulation following the intermittent catheterization (mean = 83.3% ± 2.8).

Conclusion

Early sacral root electric stimulation decreased the incidence of neuronal degeneration in decentralized detrusor muscle, together with improving the regenerative potential of cholinergic axons.

African Journal of Urology Vol. 7 No. 1 (Jan 2001): pp1-12

Key Words