Long‐term effects of bile on the gastric mucosa of the dog

Abstract

Bile was allowed to act on the gastric mueosa of dogs for periods of time ranging from 60 to 540 days. Then the mucosa was studied by light microscopy and morphometric techniques to determine height of the mucosa, infundihulum and glands, number of mast cells, and number of interepithelial lymphocytes. Marked acute inflammatory lesions and decrease in cellular mucin content were observed mainly in the antral mucosa exposed to bile for up to 130 days. Other changes appearing both in the antrum and fundus of the same dogs included an increase in the number of interepithelial lymphocytes, architectural distortion, and decrease in the height of the mucosa, the infundibulum being the most affected component in the antrum and the glands in the fundus. Positive alkaline phosphatase activity was observed in the antral area up to 130 days. With continuous exposure to bile, the gastric mucosa appeared to undergo adaptation, since all the described alterations gradually disappeared.Gastric ulcers are believed to result from decreased resistance to various aggressive factors [1][2][3][4][5][6][7][8]. Biliary reflux has been proposed as a possible etiologic factor in gastric ulcer. We have previously described some of the acute effects of bile on the gastric mucosa of the dog [9]. In the present studies, we performed a quantitative analysis of the long-term effects of bile on the gastric mucosa of the dog. The aim of this study was to find out if there is any similarity between the long-term effects of bile on the gastric mucosa and the lesions of naturally occurring gastric ulcer. 471 Materials and MethodsThirty-six mongrel dogs of both sexes, weighting 9-20 kg and fasted for 24 hours were allocated into 6 groups, according to the duration of the cholecystographic anastomosis: A--60 days, n = 6; B--90 days, n = 5; C--130 days, n = 6; D--365 days, n = 5; E--540 days, n = 5; and F--9 control dogs without a cholecystogastrostomy. The dogs were anesthetized with sodium pentobarbital (30 mg/kg, intravenously) and through a median laparotomy, the terminal end of the common bile duct was ligated and an anastomosis was established between the fundus of the gallbladder and the antrum-fundus junction of the stomach. The animals received a liquid diet during the first 24 hours after surgery and gradually resumed a normal diet. The cholecystogastrostomy was maintained for variable periods of time, namely, 60, 90, 130, 365, and 540 days. At the end of these periods of time, a median laparotomy was performed under anesthesia, and the ligation of the bile duct and patency of the anastomosis were verified. The stomach was excised, opened along the greater curvature, examined macroscopically, and then fixed in Bouin solution for 24 hours.Samples from the antral, fundic, and perianastomotic mucosa were collected and processed. Microscopic sections were stained with hematoxylin-eosin, PAS, and toluidine blue [10]. Alkaline phosphatase was identified histochemically by the Gomori technique.Mast cells and interepithelial lymphocytes were counte...