External urethral sphincter activity in diabetic rats.
Authors Liu G, Lin YH, Yamada Y, Daneshgari F
Submitted By Firouz Daneshgari on 2/4/2009
Status Published
Journal Neurourology and urodynamics
Year 2008
Date Published 4/1/2008
Volume : Pages 27 : 429 - 434
PubMed Reference 18351620
Abstract AIM: To examine the temporal effects of diabetes on the bladder and the external
urethral sphincter (EUS) activity in rats. METHODS: Female Sprague-Dawley rats
(n = 24) were divided into two groups: streptozotocin-induced diabetic rats and
age-matched controls. Cystometrograms (CMGs) were taken under urethane
anesthesia and electromyograms (EMG) of the EUS were evaluated in all rats at 6
and 20 weeks after diabetes induction. After EMG assessment, the tissues of the
urethra were harvested for morphological examination. RESULTS: Diabetes caused
reduction of body weight, but an increase in bladder weight. CMG measurements
showed diabetes increased threshold volume, contraction duration, high-frequency
oscillations (HFO), and residual volume. Peak contraction amplitude increased in
6-week but not 20-week diabetic rats. EUS-EMG measurements showed increased
frequency of EUS-EMG bursting discharge during voiding in 6-week diabetic rats
(8.1 +/- 0.2 vs. 6.9 +/- 0.6/sec) but not in 20-week (5.8 +/- 0.3 vs. 6.0 +/-
0.2/sec) diabetic rats compared with controls. EUS-EMG bursting periods were
also increased in both 6-week and 20-week diabetic rats compared with controls.
EUS-EMG silent periods were reduced in 6-week diabetic rats, but were not
changed in 20-week diabetic rats compared with controls. Active periods did not
change in 20-week diabetic rats, but increased in 6-week diabetic rats compared
with controls. Morphometric analysis showed atrophy of the EUS after 20 week but
not 6 weeks of DM induction. CONCLUSIONS: Our data indicates diabetes causes
functional and anatomical abnormalities of the EUS. These abnormalities may
contribute to the time-dependent bladder dysfunction in diabetic rats.

Investigators with authorship
Firouz DaneshgariCase Western Reserve