Sphincter of Oddi and gastrointestinal motility disturbance following alcohol administration in the opossum.
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Ampulla of Vater↗
Biomedical subjects
F G Moody
Publications and source records attributed to F G Moody.
Endotoxemia after relief of biliary obstruction by internal and external drainage in rats.
Systemic and portal endotoxemia were studied in rats with biliary obstruction and after relief of the obstruction by internal and external drainage. Endotoxemia was increased after bile duct ligation (p less than 0.001) compared with control values. The incidence of systemic and portal endotoxemia was significantly reduced after internal drainage (p less than 0.001). A significantly higher incidence of portal (86 percent) and systemic (57 percent) endotoxemia, however, was found after external drainage. The persistence of endotoxemia after external drainage, when serum bilirubin levels returned to normal units, indicates that bile flow is important in controlling endotoxemia during preoperative biliary drainage. These results suggest that the systemic endotoxemia observed after relief of obstruction by external drainage may contribute to the increased mortality, as found in previous rat studies. This observation may contribute to an understanding of why patients with preoperative external drainage of biliary obstruction have a higher incidence of septic complications.
Animals↗
Gastrointestinal motility following small bowel obstruction in the opossum.
The motility of the gastrointestinal tract of six opossums with total and four with partial small bowel obstruction was evaluated. Following the establishment of small bowel obstruction, the migrating myoelectric complex was substituted by a new pattern which was characterized by periods of intense spike activity interspersed with quiescent periods. In the experiments with total intestinal obstruction, the frequency and duration of the periods of intense spike activity were related to the recording site and the time after establishment of intestinal obstruction. The frequency of spike bursts in the ileum proximal and distal to the obstruction was the greatest in the first 2 days after the establishment of the obstruction, while in the antrum and proximal small bowel, the frequency of bursts of spike potentials increased gradually from the first to the fourth postobstruction day (P less than 0.01). However, there was no change in the frequency, duration, and localization of periods of intense spike activity during the 5 days following the establishment of partial intestinal obstruction. We concluded that following intestinal obstruction, the migrating myoelectric complex is substituted by a myoelectric pattern that is characterized by periods of intense spike activity interspersed with quiescent periods. In the animals with total intestinal obstruction, the periods of increased motility are initially more frequent in the bowel proximal and distal to the obstruction and afterwards in the stomach and upper small bowel.
Animals↗
Changes in nutritional status associated with obstructive jaundice and biliary drainage in rats.
Effect of bile duct ligation (BDL) and internal biliary drainage on food intake and nutritional status was studied in rats and compared with sham and pair-fed animals. During week 1, food intake of BDL animals was reduced (p less than 0.05), resulting in weight loss (p less than 0.05). In weeks 2 and 3, food intake, nitrogen balance, and weight gain were similar in all groups. Internal biliary drainage or sham operation after 3 wk produced transient changes in food intake and N2 balance. Serum albumin fell in all groups, returned to normal in sham (3.2 +/- 0.1 g/dl) and pair-fed (3.1 +/- 0.1 g/dl), but persisted in BDL rats (2.4 +/- 0.2 g/dl, p less than 0.001). Jaundice was associated with anemia. Although BDL produces transient changes in food intake, weight gain, and N2 balance, anorexia and malnutrition are not features of this animal model. Nutritional risk factors associated with hyperbilirubinemia are probably due to changes in intermediary metabolism.
Animals↗
Serotonin increases the velocity of propagation and frequency of the migrating myoelectric complexes.
The effect of serotonin on the myoelectric activity of the gastrointestinal tract was evaluated in seven opossums. Continuous intravenous administration of serotonin reduced the cycle duration of the migrating myoelectric complex and increased the velocity of propagation of the phase III. These changes were dose-dependent and were observed only with high doses of serotonin of 0.1 mg kg-1 h-1 or more. Infusion of 0.01 mg kd-1 h-1 had no effect on the motility of the gastrointestinal tract. The motility changes occurred in all segments of the gastrointestinal tract studied and were characterized by a continuous and organized increase in the velocity of propagation of the activity front (phase III) of the migrating myoelectric complex from the antrum to the terminal ileum. The cycle duration of the two migrating myoelectric complexes following administration of methysergide at 1.0 mg kg-1 was similar to the control migrating myoelectric complexes. We concluded that continuous infusion of serotonin in the opossum increases the velocity of propagation of the phase III of the migrating myoelectric complex from the antrum to the terminal ileum.
Animals↗
Effect of 16,16-dimethyl prostaglandin E2 on the myoelectric activity of the gastrointestinal tract of the opossum.
Myoelectric recordings of the opossum gastrointestinal tract were performed during continuous infusion of 16,16-dimethyl prostaglandin E2 at 0.1, 1, 2 and 5 micrograms/kg X h. Continuous administration of prostaglandin caused a dose-dependent reduction of the duration of the migrating myoelectric complex cycle and an increase in the velocity of phase III migration from the duodenum to the terminal ileum. The reduction of the migrating myoelectric complex cycle was due to a shortening of the duration of both phase I and II. Bolus administration of 16,16-dimethyl prostaglandin E2 caused intense spike activity for 2-4 min in all recording sites simultaneously. Administration of indomethacin did not change the myoelectric activity of the gastrointestinal tract. Infusion of prostaglandin E2 caused diarrhoea in eight of forty experiments. These changes in gastrointestinal motility may be important contributory factors in the pathogenesis of prostaglandin-induced diarrhoea.
16,16-Dimethylprostaglandin E2↗
Intestinalization of pancreatic fragments in dogs.
A new operative procedure for the preservation of pancreatic fragments is introduced ("intestinalization") in which vascularized fragments are placed inside a jejunal pouch. This step is done to manage all secretions, lymph and potential debris coming from the pancreas; to maintain the primary portal drainage of insulin; to avoid vascular operations, and to keep the fragment in a denervated state and still preserve its endocrine function to prevent diabetes. The procedure was compared with conventional end to end pancreaticojejunostomy. Sixteen dogs were studied. Group 1 consisted of four dogs that had intestinalization of the pancreatic tail. Group 2 is made up of eight dogs that had complete resection of the remaining duodenal portion of the gland as well as intestinalization of the pancreatic tail. Group 3 consisted of four dogs that had end to end pancreaticojejunostomy to the isolated tail and complete resection of the duodenal portion of the gland as those dogs in group 2. No dog became diabetic during the time of observation (up to one year)--fasting glucose levels and K values in glucose tolerance tests remained normal. Insulin peak values at ten minutes were lower postoperatively. However, return to fasting levels occurred equally fast postoperatively. There was no difference among the groups. The most important morphologic finding in the intestinalized fragments was a firm capsule surrounding the tissue after two weeks. Exocrine atrophy was present in both groups 2 and 3 after one year. No reinnervation of intestinalized pancreas was seen. Intestinalization may offer an alternative to pancreatic resection especially when heterotopic autotransplantation is considered.
Amylases↗
The role of biliary obstruction in the pathogenesis of acute pancreatitis in the opossum.
Pancreatitis was induced in the opossum by occluding the common bile duct above or below the entrance of the pancreatic duct. The common channel theory was tested by evaluating the effect of preligation of the pancreatic duct to prevent the reflux of bile after ligation of the distal common duct. The severity of the disease was determined by histologic grading of the degree of pancreatic tissue necrosis. Serum amylase, lipase, and calcium were determined. Concomitant obstruction of the biliary and pancreatic ducts produced severe necrotizing pancreatitis whether or not bile reflux was present. Pancreatic ductal obstruction alone was associated with acinar atrophy and mild interstitial pancreatitis. Biliary obstruction alone above the entrance of the pancreatic duct resulted in marked hyperemia of the gland but without histologic evidence of pancreatic inflammation. A positive bacterial culture of the pancreas was obtained in only four of 36 opossums in a distribution to suggest random contamination. There was an inverse correlation between calcium levels and the degree of tissue necrosis. This study demonstrates that biliary obstruction rather than bile reflux into the pancreas is a requisite for the pathogenesis of severe biliary pancreatitis in this model.
Acute Disease↗
Influence of autonomic drugs on the motility of the sphincter of Oddi in the opossum.
We have evaluated the effect of various autonomic drugs on the electromyographic activity of the sphincter of Oddi and the small intestine of seven opossums. Hexamethonium bromide and atropine sulfate abolished and bethanechol increased the frequency of spike bursts in the sphincter of Oddi and duodenum. Phenylephrine and epinephrine increased the number of spike bursts in the sphincter of Oddi after a short period of stimulation. No spike potentials were seen in the duodenum after infusion of norepinephrine. Clonidine and dobutamine decreased spike burst activity in the sphincter of Oddi and duodenum. Terbutaline also decreased the frequency of spike bursts in the sphincter of Oddi but did not change the number in the duodenum. Prior infusion of antagonists blocked partially or totally the effect of all respective agonists except for yohimbine, which did not inhibit the effect of clonidine. These findings suggest that the sphincter of Oddi may have cholinergic, alpha 1, alpha 1, beta 1 and beta 2-adrenergic receptors. Cholinergic agonists stimulate and alpha 2, beta 1 and beta 2-adrenergic agonists inhibit the motility of the sphincter of Oddi and the small intestine. Alpha-adrenergic agonists stimulate the motility of the sphincter of Oddi and inhibit the motility of the small intestine.
Ampulla of Vater↗
Gallbladder contractility and mucus secretion after cholesterol feeding in the prairie dog.
The purpose of our study was to evaluate changes in gallbladder contractility and mucus secretion in vitro during the early stages of gallstone formation in prairie dogs. Thirty-two animals were divided into five groups. Control animals were fed a trace cholesterol diet. Experimental animals were fed a high-cholesterol diet for 3, 6, 8, and 14 days, respectively. Muscle stress was measured in response to cholecystokinin octapeptide in each of the groups. The maximal stresses in the 8-day diet (68 +/- 7 gm/cm2) (mean +/- SEM) and 14-day diet animals (83 +/- 7 gm/cm2) were found to be significantly lower than those of the control animals (137 +/- 12 gm/cm2). The stress in 3-day diet animals was significantly greater (224 +/- 23 gm/cm2). A significant increase in mucus secretion was observed only in 14-day diet animals (11.0 +/- 0.5 X 10(6) dpm/gm dry wt) compared with the control animals (6.4 +/- 1.0 X 10(6) dpm/gm). The decrease in contractility may be the initial event in cholesterol stone formation, and the prolonged exposure of the gallbladder epithelium to crystals may stimulate the release of mucus into the bile.
Animals↗
Changes in body composition and dietary intake after gastric partitioning for morbid obesity.
Patients who undergo gastric partitioning for morbid obesity lose weight rapidly in the first year after surgery. This study measured changes in body composition and dietary intake at 3 months, 6 months, and 1 year after gastric partitioning. Body composition was determined by total-body gamma-ray spectrometry. Records of dietary intake were computer analyzed for nutritional content with the Ohio State Nutrient Analysis Data Base. All patients lost a significant amount of weight at 3, 6, and 12 months after surgery. Loss of lean tissue comprised 25% of the total weight loss at 3 months but only 20% of the total at 1 year. Before surgery the mean energy intake was 2592 kcal and the mean protein intake was 92 gm. After 3 months, energy intake was 745 kcal and protein 32 gm. One year after surgery energy intake was 1089 kcal and protein 41 gm per day. We conclude that patients lose a significant amount of lean body tissue in the first 3 months after gastric partitioning but the loss does not continue, and 1 year after surgery some lean tissue is actually regained. This initial loss is due to a combination of a very restrictive dietary regimen and the body's metabolic response to surgery. After the first 3 months adaptation occurs and lean tissue is spared.
Adult↗
Estimation of hepatic blood flow by hydrogen gas clearance.
The hydrogen gas clearance technique was evaluated to estimate regional hepatic blood flow. Initially, the H2 gas method was compared to the indocyanine green clearance in mini pigs. The blood flow measured by the H2 gas method (0.49 +/- 0.03 ml/min/gm) was only 39% of the calculated blood flow by the indocyanine green method (1.26 +/- 0.14 ml/min/gm). The blood flow determined by H2 gas decreased to 0.06 +/- 0.04 ml/min/gm after ligation of the hepatic artery. No difference in blood flow was found by simultaneous measurements on the left (0.89 +/- 0.1 ml/min/gm) and right (0.96 +/- 0.13 ml/min/gm) liver lobes in rats. After ligation of the left hepatic artery in the rats, a delayed response to H2 application was present and the determined blood flow (0.14 +/- 0.02 ml/min/gm) was significantly reduced (p less than 0.001) compared with the right liver lobe H2 determined blood flow as a control. No current was generated after ligation of the left hepatic artery and the portal vein indicating that there was no blood flow measured by the gas H2 method. The results indicate that the H2 gas clearance technique may be a method that assesses hepatic arterial liver perfusion rather than estimates total hepatic blood flow. The safety and simplicity of the H2 gas clearance technique may make it suitable for clinical application in serial measurement of hepatic arterial blood flow in man.
Animals↗
Effects of gastrointestinal hormones on Oddi's sphincter and duodenal myoelectric activity and pancreatobiliary pressure. Studies in the opossum.
Myoelectric activity of Oddi's sphincter and duodenum was correlated with common duct and pancreatic duct pressures in conscious opossums after infusion of the following substances: cholecystokinin, pentagastrin, glucagon, secretin, and acetylcholine. Cholecystokinin and pentagastrin increased and glucagon and secretin decreased the frequency of spike potentials in Oddi's sphincter and the duodenum. Acetylcholine was associated with the largest increase in spike potentials in both Oddi's sphincter and the duodenum. Although there was variation in the number of pressure elevations related to Oddi's sphincter spike potentials, the baseline pressure remained constant during administration of the hormones. Acetylcholine infusion increased the biliary and pancreatic pressures to 29 and 31 mm Hg, respectively. We conclude that gastrointestinal hormones may have an important role in regulating the excretion of bile and pancreatic juice into the duodenum.
Acetylcholine↗
Gastrointestinal myoelectric activity following abdominal operations in the opossum.
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Abdomen↗
Pathogenesis and treatment of inflammatory lesions of the papilla of Vater.
Benign papillary disease is an uncommon entity. For the small percentage of the population afflicted, however, it is a very real, incapacitating disease. In an attempt to alleviate the distressing pain associated with papillary disease, we performed a transampullary septectomy on 105 patients, between the years of 1972 to 1985. There were no operative deaths, and only five serious complications. The findings at exploration were almost equally distributed between stenosing papillitis (53), and septitis (45). The papilla was normal in 7. Histologic findings of inflammation were more common in the former, while fibrosis was seen more frequently with the latter. Long term follow-up (1 to 13 years) in 94 patients revealed complete pain relief in 50 per cent and improvement in 75 per cent Gallstones, pancreatitis, and peptic ulcer appeared to play a role in the pathogenesis of this obscure, rare, and disabling disease.
Abdomen↗
Experimental evaluation of gastric banding for treatment of morbid obesity in pigs.
The effectiveness and complications of gastric banding were evaluated in 15 miniature pigs. A Gore-tex or Dacron graft was employed to encircle the stomach. The animals were divided into five groups, three pigs in each group. Group 1 had a 13 mm pouch stoma with a Gore-tex band, Group 2 had a 16 mm pouch stoma with a Gore-tex band, Group 3 had a 13 mm pouch stoma with a Dacron band, Group 4 had a 16 mm pouch stoma with a Dacron band, and Group 5 had a sham operation. The weight variation in the control group was significantly higher than that in the other groups at the ninth postoperative week (p less than 0.05). There was no significant difference among Groups 1, 2, 3, and 4. The gastric band had migrated distally in seven pigs. It was located in the body of the stomach in four animals and in the pylorus in three. These three pigs died from stenosis of the pylorus. The band had eroded and penetrated all stomach layers in three other animals. There was no difference in the incidence of postoperative complications between the Gore-tex and Dacron band groups. The use of this simple operation in the treatment of the morbidly obese patient should be applied with caution.
Animals↗
A new method for correlating pancreatic and biliary duct pressures and sphincter of Oddi electromyography.
Myoelectric activity of the sphincter of Oddi and duodenum was correlated with pancreatic and biliary duct pressures in eight opossums, in both the fasted and fed states. Four bipolar electrode pairs were implanted in the sphincter of Oddi and duodenum. A polyethylene T tube was placed in the pancreatic duct. The common duct was cannulated through a small bile duct. This method allowed pressure recording for several weeks and avoided interference with the flow of bile or pancreatic juice into the duodenum. The frequency of slow waves was the same in the sphincter of Oddi and duodenum (19 per minute). The variation in the frequency of spike potentials in the sphincter of Oddi correlated to that of the migrating myoelectric complex in the duodenum. The average frequency of slow waves that have superimposed spike potentials in the sphincter of Oddi and duodenum was 3.0 and 0 in phase 1, 4.7, and 6.2 in phase II, 6.1 and 15.1 in phase III, and 3.4 and 6.3 in phase IV, respectively. The average duration of a migrating myoelectric complex cycle was 92 minutes. After feeding, the interdigestive phases of the migrating myoelectric complex were abolished and substituted by a feeding activity pattern that was characterized by an average number of sphincter of Oddi and duodenum spikes of 6.6 and 10.7, respectively. The mean fasting pressure in the pancreatic and biliary duct was 15 and 13 mmHg, respectively. Pressure changes were of two types--synchronous with respiratory movements and with each sphincter of Oddi spike potential. There was no variation in the baseline pressure during the migrating myoelectric complex phases and the fed state. It is concluded that the sphincter of Oddi of the fasting opossum exhibits cyclic changes in the number of spike potentials that correlate with the migrating myoelectric complex in the duodenum. However, the number and amplitude of spike potentials are different in the sphincter of Oddi and duodenum. There is no change in the baseline pressure during fasting and feeding states, and a temporary pressure elevation synchronic with each sphincter of Oddi spike potential was observed.
Action Potentials↗
Effect of alcohol upon myoelectric activity of the gastrointestinal tract and pancreatic and biliary duct pressures.
Myoelectric activity of the antrum, duodenum and sphincter of Oddi was recorded from 12 conscious opossums. The common duct and the pancreatic duct were cannulated for pressure measurements. Recordings were made in the fasted state and after gastric or duodenal administration of ethanol. Alcohol was instilled during phase I (55 experiments) or phase II (ten experiments) of the migrating myoelectric complex. Administration of alcohol caused the appearance of phase III-like activity in five to ten minutes in 91 per cent of the experiments. Pancreatic duct and common duct pressure oscillations occurred synchronously with respiratory movements and with sphincter of Oddi spike potentials. There was an increase in the number of pressure elevations related to the increase in sphincter of Oddi spike potentials after alcohol administration; however, base line pressures remained constant. It is concluded that the administration of alcohol into the stomach or duodenum causes the appearance of phase III-like activity and that there is no change in the base line pressure after the instillation of alcohol.
Animals↗