Korean J Anat.  2004 Oct;37(5):403-410.

Partial Outlet Obstruction Induced Alterations of Rat Urinary Bladder Muscle

• Han HS
• Kim IK
• Kim DY

Abstract

Partial outlet obstruction induced by benign prostatic hypertrophy or urethral stricture are common urologic conditions showing voiding dysfunction. This study was performed to compare the effects of short-term partial outlet obstruction on the contractile responses to different stimuli and to elucidate the mechanism of altered contractile response during the development of significant voiding dysfunction. Sprague-Dawley rats, 10 week old, were subjected to partial outlet obstruction for 7 days. Contractile responses of the urinary bladder detrusor muscle strips to electrical field stimulation (1, 2, 5, 10 and 20 Hz), KCl (50 and 100 mM) and carbachol (10(-9 to 5) M) were measured. Total protein and DNA contents of the bladder were measured. Connexin 43 mRNA expression was measured using RT-PCR and connexin 43 protein was observed in the fixed bladder tissue using immunohistochemistry. The electrical field stimulation-induced contractile response and KCl-induced contraction was not changed after partial outlet obstruction. Contraction induced by carbachol was enhanced by the partial outlet obstruction. Total protein and DNA contents were increased in the partial outlet obstruction group. Connexin 43 mRNA and protein expression were detectable in the normal bladders and increased after 7 days of obstruction. These results suggest that the altered contractile responses during the early stage of the partial outlet obstruction are the result of the changes of the contraction mechanisms or structure of bladder muscle. Connexin 43 may play an important role in those alterations.

Keyword

Urinary bladder; Outlet obstruction; Contractility; Connexin 43

MeSH Terms

Animals
Carbachol
Connexin 43
DNA
Immunohistochemistry
Prostatic Hyperplasia
Rats*
Rats, Sprague-Dawley
RNA, Messenger
Urethral Stricture
Urinary Bladder*
Carbachol
Connexin 43
DNA
RNA, Messenger