Ureterovesical junction obstruction causes increment in smooth muscle contractility, and cholinergic and adrenergic activity in distal ureter of rabbits.
OBJECTIVE
The controversy in management of primary obstructed megaureter necessitates further elucidation of the underlying pathophysiology. We evaluated smooth muscle contractility, and cholinergic, adrenergic and serotonergic activity of rabbit distal ureters after ureterovesical junction (UVJ) obstruction.


METHODS
Sham (SH) operation, partial obstruction (PO) and complete obstruction (CO) of the right UVJ were performed in rabbits. Three weeks later, distal ureters were isolated; spontaneous contractions (SC), contractile responses to electrical field stimulation (EFS), high KCl, carbachol, phenylephrine and serotonin were recorded.


RESULTS
SC amplitudes increased in CO compared to PO and SH (p<0.001). SC frequency was higher in CO (p<0.05). EFS-induced contraction amplitudes were greater in CO than other groups (p<0.05). High KCl-induced contractions were greater in CO (p<0.001) and PO (p<0.01). Carbachol-induced contractility was enhanced in CO and PO (p<0.05). Contractile response to phenylephrine was greater in CO than other groups (p<0.05). Serotonin induced contractile responses in CO and PO, greater in CO (p<0.05). UVJ obstruction also increased spontaneous contractility in contralateral PO and CO ureters.


CONCLUSIONS
UVJ obstruction increased spontaneous and neurotransmitter-induced contractions in an obstruction grade-dependent manner. Obstruction also altered contractility of the contralateral ureters. Our findings may serve to provide further understanding of the pathophysiology of megaureter.
Department of Pediatric Surgery, Hacettepe University, Faculty of Medicine, Sihhiye, Ankara, 06100 Turkey. Electronic address: suleyal@hacettepe.edu.tr.
Sule
S
Yalcin
Mert
M
Ertunc
Burak
B
Ardicli
Ismail M
IM
Kabakus
Taskin S
TS
Tas
Yildirim
Y
Sara
Rustu
R
Onur
Ibrahim
I
Karnak
D000322:Adrenergic Agonists / Q000494:pharmacology; D000320:Adrenergic Fibers / Q000502:physiology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000503:physiopathology*; D010528:Peristalsis / Q000187:drug effects / Q000502:physiology; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D011897:Random Allocation; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology; D014513:Ureter / Q000294:innervation; D014517:Ureteral Obstruction / Q000503:physiopathology*
D000322:Adrenergic Agonists; D018679:Cholinergic Agonists; D010656:Phenylephrine; D012701:Serotonin; D011189:Potassium Chloride; D002217:Carbachol
Contractility; Distal ureter; Obstruction; Ureterovesical junction