V. Pikov et al., ASSESSMENT OF LOWER URINARY-TRACT FUNCTIONAL DEFICIT IN RATS WITH CONTUSIVE SPINAL-CORD INJURY, Journal of neurotrauma, 15(5), 1998, pp. 375-386
Citations number
61
Categorie Soggetti
Neurosciences,"Clinical Neurology","Emergency Medicine & Critical Care
Traumatic spinal cord injury (SCI) produces lower urinary tract (LUT)
dysfunction that has been studied in surgical transection models. Our
aim was to assess LUT functional deficit in a clinically relevant mode
l of incomplete SCI to investigate how partial preservation of suprasp
inal connections might affect LUT dysfunction. Standardized weight-dro
p contusion (10 g x 2.5 cm) or complete transection, was produced at T
8 in female Sprague-Dawley rats. Behavioral tests were used to assess
hind limb sensorimotor function at Day 1 after surgery and weekly ther
eafter. The urometric experiments were conducted on groups (n = 7) of
uninjured rats and on injured rats during Weeks 1 and 2 after SCI (bef
ore and after spontaneous voiding was established) as well as Week 2 a
fter a complete transection (n = 3), Under anesthesia, the bladder was
continuously perfused with saline, Changes in bladder pressure and ex
ternal urethral sphincter (EUS) electrical activity were monitored. Th
e bladder was then dissected and weighed and both the bladder and spin
al cord were fixed for pathoanatomical analyses. Our results indicate
that several aspects of LUT dysfunction after contusive SCI were simil
ar to transection, e.g., reduction of voiding efficiency (similar to 5
% of normal value), decrease in inter-contraction interval (47%), incr
ease in bladder capacity (8-fold), and weight (4.6-fold), One aspect a
ppeared different from transection-partial recovery from acute bladder
/sphincter dyssynergia. Because the coordination of bladder and EUS fu
nction is mediated by brainstem pathways, partial recovery of synergy
after SCI was likely due to sparing of some relevant bulbospinal proje
ctions as was confirmed by retrograde transneuronal viral tracing.