Alterations in spontaneous contractions of rat proximal and distal colon after peritonitis.
OBJECTIVE
The aim of this study was to investigate the effect of peritonitis on spontaneous contractions of distal and proximal colon smooth muscle isolated from rats.


METHODS
Peritonitis was induced by cecal ligation and puncture in 8 rats. Another group of 8 rats underwent a sham operation and acted as controls. Twenty-four hours after the operation, the rats were killed; and their distal and proximal colon smooth muscle was excised and placed in circular muscle direction in a 10-mL organ bath. Changes in the amplitude and frequency of contractions were analyzed before and after the addition of antagonists.


RESULTS
Peritonitis induced the increase in the amplitude and frequency of spontaneous contractions. In both distal and proximal colon of the control group, the amplitude of spontaneous contractions was elevated by N(G)-nitro-L-arginine and tetrodotoxin; but the frequency of spontaneous contractions was significantly elevated only in the presence of N(G)-nitro-L-arginine. In both distal and proximal colon of the peritonitis group, the enhanced amplitude and frequency were significantly decreased and returned to control values in the presence of celecoxib.


CONCLUSIONS
Peritonitis induces the increase in the amplitude and frequency of spontaneous contractions of distal and proximal colon, which can be attributed to a loss of inhibitor nitrergic and other neural control or rise of cyclooxygenase-2 levels.
Yildiz
Turan
T
Department of Pediatric Surgery, Cumhuriyet University, Faculty of Medicine, 58140 Sivas, Turkey.
Koyluoglu
Gokhan
G
Bagcivan
Ihsan
I
Kaya
Tijen
T
Karadas
Baris
B
Saraç
Bülent
B
Cankorkmaz
Levent
L
D000704:Analysis of Variance; D000818:Animals; D003106:Colon / Q000201:enzymology / Q000382:microbiology / Q000503:physiopathology*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000201:enzymology / Q000503:physiopathology*; D010538:Peritonitis / Q000201:enzymology / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar
D051546:Cyclooxygenase 2