Effects of naloxone on regional norepinephrine content of the rabbit urinary bladder after electrical pelvic floor stimulation.
OBJECTIVE
Effect of opioid blockade on regional norepinephrine content of the rabbit urinary bladder was investigated under electrical pelvic floor stimulation.


METHODS
Norepinephrine content of the bladder body and base of the rabbit was estimated by high-performance liquid chromatography in the following four subgroups: control group; group 1, treated by electrical stimulation; group 2, treated by naloxone alone; and group 3, treated by electrical stimulation and naloxone.


RESULTS
Intravenous administration of naloxone (group 2) caused depletion of norepinephrine content in the bladder body (P < 0.001). Norepinephrine content in the bladder base was also reduced, although this difference was not statistically significant. Electrical stimulation to the pelvic floor musculature (group 1) increased norepinephrine content both in the bladder base and the body (P < 0.01). Such a norepinephrine elevation disappeared in the rabbit treated by electrical stimulation plus naloxone (group 3). Norepinephrine content of this group was almost the same as those treated by naloxone alone.


CONCLUSIONS
Opioid blockade appeared to block the hypogastric nerve activation induced by electrical pelvic floor stimulation.
Ishigooka
M
M
Department of Urology, Yamagata University, School of Medicine, Japan.
Hashimoto
T
T
Hayami
S
S
Suzuki
Y
Y
Sasagawa
I
I
Nakada
T
T
D000818:Animals; D004558:Electric Stimulation; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D009638:Norepinephrine / Q000032:analysis*; D017773:Pelvic Floor; D011817:Rabbits; D001743:Urinary Bladder / Q000737:chemistry* / Q000187:drug effects
D009270:Naloxone; D009638:Norepinephrine