Decreased cellular membrane expression of gap junctional protein, connexin 43, in rat detrusor muscle with chronic partial bladder outlet obstruction.
OBJECTIVE
To investigate alterations in gap junctional protein, connexin-43 (Cx-43), in the rat detrusor muscle with partial bladder outlet obstruction (P-BOO). Muscle cell actions, such as detrusor contractions, are thought to be synchronized by way of gap junctional intercellular communication. Gap junctions may play an important role in voiding, and P-BOO is a common medical problem.


METHODS
A total of 33 female Wistar rats (12 weeks old) were divided into a P-BOO group and a sham-operated control group and were killed at 2, 4, and 8 weeks after surgery. Cystometric investigation, the alteration of gap junction, and Cx-43 protein expression, which compose the gap junction, were examined.


RESULTS
The number of gap junctions was decreased in the P-BOO rat bladder. Furthermore, decreased cellular membrane expression of Cx-43 proteins was detected in rat detrusor muscle cells more than 4 weeks after surgery. The gap junctions of the detrusor muscle cell membranes were significantly fewer in number in the P-BOO rats with no detrusor contractions.


CONCLUSIONS
These data suggest that the normal signals that contribute to voiding function could be transported directly through the gap junctions. Voiding dysfunction may be caused by the disruption of gap junctional intercellular communication.
Mori
Ken-Ichi
K
Division of Nephro-Urology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. moriken@net.nagasaki-u.ac.jp
Noguchi
Mitsuru
M
Matsuo
Manabu
M
Nomata
Koichiro
K
Suematsu
Takashi
T
Kanetake
Hiroshi
H
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D002908:Chronic Disease; D018031:Connexin 43 / Q000378:metabolism*; D005260:Female; D017629:Gap Junctions / Q000473:pathology*; D007150:Immunohistochemistry; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000378:metabolism* / Q000503:physiopathology / Q000648:ultrastructure; D001748:Urinary Bladder Neck Obstruction / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D014563:Urodynamics
D018031:Connexin 43