The Effect of Urocortin 1 on Motility in Isolated, Vascularly Perfused Rat Colon / 대한소화기학회지

BACKGROUND/AIMS: Urocortin 1, a corticotropin-releasing factor related peptide, increases colonic motility under stressful conditions. We investigated the effect of urocortin 1 on colonic motility using an experimental model with isolated rat colon in which the blood flow and intestinal nerves were preserved. Furthermore, we assessed whether this effect was mediated by adrenergic or cholinergic nerves. METHODS: Colonic motility was measured in the proximal and distal parts of resected rat colon. The colon resected from the peritoneum was stabilized, and then urocortin 1 (13.8, 138, 277, and 1,388 pM) was administered via a blood vessel. Motility index was measured in the last 5 min of the 15 min administration of urocortin 1 and expressed as percentage change from baseline. Subsequently, the change in motility was measured by perfusing urocortin 1 in colons pretreated with phentolamine, propranolol, hexamethonium, atropine, or tetrodotoxin. RESULTS: At concentrations of 13.8, 138, 277, and 1,388 pM, urocortin 1 increased the motility of proximal colon (20.4+/-7.2%, 48.4+/-20.9%, 67.0+/-25.8%, and 64.2+/-20.9%, respectively) and the motility of distal colon (3.3+/-3.3%, 7.8+/-7.8%, 71.1+/-28.6%, and 87.4+/-32.5%, respectively). The motility induced by urocortin 1 was significantly decreased by atropine to 2.4+/-2.4% in proximal colon and 3.4+/-3.4% in distal colon (p<0.05). However, tetrodotoxin, propranolol, phentolamine, and hexamethonium did not inhibit motility. CONCLUSIONS: Urocortin 1 increased colonic motility and it is considered that this effect was directly mediated by local muscarinic cholinergic receptors.

A Case of Malignant Biliary Stricture Mimicking Benign Stricture coincided with Clonorchis sinensis / 대한췌담도학회지

Accurate and early diagnosis of indeterminate bile duct stricture is difficult. There are numerous cases suggesting similarity between benign tumors and malignancy. Therefore, meticulous evaluation with endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound and computed tomography (CT) is necessary. A 50 year-old male presented with painless jaundice. Abdominal CT scan showed distal biliary stricture without definite pancreatic mass. Repeated brush cytology and endobiliary biopsy during ERCP did not reveal malignancy except for eggs of Clonorchis sinensis. The patient declined surgical resection without definite evidence of malignancy. Abdominal CT scan one month later showed progressive parenchymal atrophy and pancreatic duct dilatation. The patient underwent pylorus preserving pancreatoduodenectomy. Pathology revealed pancreatic adenocarcinoma in the head portion. Since accurate preoperative diagnosis of malignant biliary obstruction can be evasive, patients with biliary stricture should undergo evaluation with high index of suspicion.