Pancreatic hypersecretion in liver disease

Stimulatory effects of bilirubin on amylase release from isolated rat pancreatic acini

Considered to be an etiologic factor of acute pancreatitis, hypersecretion of pancreatic juice and digestive enzymes is often associated with hyperbilirubinemia. We explored the intracellular mechanisms through which bilirubin affects pancreatic exocrine secretory function by examining the effect of bilirubin on isolated rat pancreatic acini. Bilirubin stimulated amylase release in a concentration- and time-dependent manner, significantly increasing amylase release at concentrations >5 mg/100 ml and after 15 min of incubation. Coincubation of bilirubin with vasoactive intestinal polypeptide, 8-bromo-cAMP, or A-23187 had a synergistic effect on amylase release, whereas coincubation with CCK-8, carbamylcholine, or 12-O-tetradecanoylphorbol 13-acetate had an additive effect. Bilirubin did not affect acinar cAMP content or Ca(2+) efflux. Intracellular Ca(2+) pool depletion had no influence on bilirubin-evoked amylase release. The protein kinase C (PKC) inhibitors staurosporine and calphostin C partially but significantly inhibited bilirubin-stimulated amylase release, whereas the PKA inhibitor H-89 did not. The tyrosine kinase (TK) inhibitor genistein, phospholipase A(2) (PLA(2)) inhibitor indoxam, and PLC inhibitor U-73122 also inhibited amylase release. Bilirubin significantly translocated PKC activity from the cytosol to the membrane fraction and activated TK in cytosol and membrane fractions. These results indicate that bilirubin stimulates amylase release by activating PKC and TK in rat pancreatic acini and that PLC and PLA(2) partly mediate this process.

Endoscopic findings in chronic lymphocytic leukemia

Retrospective studies, based on autopsy findings, indicate that infiltration of the gastrointestinal tract complicates leukemia of all types and may be present from the esophagus to the rectum. This report presents what is believed to be the first reported case of a patient with chronic lymphocytic leukemia with evidence of esophageal, gastric, duodenal bulb, and colonic involvement confirmed by mucosal biopsy at endoscopy.

Impaired pancreatic exocrine function in rats with carbon tetrachloride-induced liver cirrhosis

BACKGROUND

Substantial numbers of studies have revealed the close correlation between chronic pancreatitis and cirrhosis in human. However, the situation with regard to pancreatic enzyme secretion is less clear.

AIM

The aim of the study was to investigate pancreatic exocrine function in rats with carbon tetrachloride-induced liver cirrhosis in rats.

METHODS

Pancreatic exocrine function and morphology in Sprague-Dawley rats with carbon tetrachloride-induced liver cirrhosis were investigated. Pancreatic exocrine functions stimulated by cholecystokinin-8 and other secretagogs were assessed in isolated pancreatic acini, and in vivo and morphological changes were studied by routine histological examination and electron microscopy.

RESULTS

The basal and cholecystokinin-8-stimulated amylase releases from acini and acinar amylase content were significantly lower in the cirrhotic rats than the control. None of the secretagogs induced the some amount of amylase release in cirrhotic as in control rats. Volume of the pancreatic juice and outputs of amylase and protein were significantly decreased under basal and cholecystokinin-8-stimulated conditions in vivo. Electron microscopy revealed most of the rough-surfaced endoplasmic reticulum accompanying less numbers of ribosomes to be dilated and some mitochondria to be swollen in cirrhotic rats.

CONCLUSION

Pancreatic exocrine functions are decreased in cirrhotic rats owing to alterations at the electron microscopic levels, reflecting an impaired acinar intracellular messenger system.

Mechanism of pancreatic hypersecretion in dogs with obstructive jaundice

Pancreatic exocrine function in experimental obstructive jaundice was examined using dogs. Outputs of pancreatic juice, bicarbonate and amylase were greater in dogs with obstructive jaundice than in control dogs. To further examine the hypersecretory mechanism in obstructive jaundice, we examined pancreatic exocrine secretion stimulated by secretin and pancreozymin in both the isolated perfused pancreas and pancreatic dispersed cell culture. The perfused pancreas stimulated with secretin and pancreozymin in dogs with obstructive jaundice showed higher secretion of volume, bicarbonate and amylase than in control dogs. Dispersed pancreatic cells of jaundiced dogs stimulated by secretin and pancreozymin released more bicarbonate and amylase into the media than dispersed cells of control dogs. These data suggest pancreatic hypersecretion in obstructive jaundice is not due to excessive serum levels of secretin and pancreozymin or impaired metabolism of these hormones.

Pancreatic hypersecretion in dogs with obstructive jaundice

We examined the hypersecretory function of the isolated, blood-perfused pancreas of dogs with experimentally obstructive jaundice. There was no difference in basal pancreatic secretion between control dogs and obstructively jaundiced dogs. Secretin- or pancreozymin-stimulated increase in total values for pancreatic juice flow, bicarbonate, protein and amylase were greater in dogs with obstructive jaundice than in control dogs; however, concentrations of bicarbonate, protein and amylase were unchanged in each group. Acetylcholine-stimulated increase in total values and concentrations of these factors were the same in dogs with obstructive jaundice and controls. These data suggest that hypersensitivity of the pancreas to secretin and pancreozymin may be one of the main mechanisms of pancreatic hypersecretion.

Gastrointestinal bleeding due to large bowel infiltration by chronic lymphocytic leukaemia

A 66 year old woman with a 9 year history of chronic lymphocytic leukaemia developed intermittent rectal bleeding for 9 months; sigmoidoscopic biopsy proved that this was due to large bowel infiltration by leukaemia. This is a very rare occurrence.

The intraductal secretin test: an adjunct to ERCP

The intraductal secretin test is an important diagnostic study. It enables the physician to determine the pancreatic secretory function in patients with known pancreatitis and to confirm the diagnosis of pancreatitis in many patients with indeterminate upper abdominal pain in whom ERCP and other diagnostic studies are normal. The IDST also provides the endoscopist and biochemist a new means to establish discriminating tests in differential diagnosis of pancreatic cancer and pancreatitis and to study the physiology of pancreatic secretion.

Postcholecystectomy syndrome and its association with ampullary stenosis

Fifty-six consecutive patients returning with recurrent or persistent upper abdominal pain after cholecystectomy were studied by endoscopic retrograde cholangiopancreatography, abdominal ultrasound and morphine neostigmine test. In 44 patients, pain recurred within 6 months after cholecystectomy. Forty patients were demonstrated on endoscopic retrograde cholangiopancreatography to have moderate to marked ampullary stenosis, which occurred as an isolated abnormality in 32 patients and in association with pancreatitis in 8. Thirteen patients were found to have pancreatitis, and 6 had retained common duct stones. In five patients no definite abnormality was demonstrated. The morphine neostigmine test was positive in 16 of 17 patients with isolated ampullary stenosis and in only 1 of 8 with pancreatitis. This test may be helpful in patients who are to undergo cholecystectomy. In those with positive results, endoscopic retrograde cholangiopancreatography would help assess the size of the ampullary sphincter so that sphincteroplasty could be done at the time of cholecystectomy in appropriate patients.

Endoscopic measurement of pancreatic juice secretory flow rates and pancreatic secretory pressures after secretin administration in human controls and in patients with acute relapsing pancreatitis, chronic pancreatitis, and pancreatic cancer

Secretory flow rates were measured inside the main pancreatic duct during endoscopic retrograde cholangiopancreatography (ERCP) in patients with acute relapsing pancreatitis, chronic pancreatitis, and pancreatic cancer and in controls after intravenous administration of secretin. Peak secretory flow rates in these groups were 5.04 +/- 1.74, 0.71 +/-1.28, 0.60 +/- 1.37, and 4.13 +/- 0.88 ml/min, respectively. Peak secretory pressures were also measured intraductally in patients with acute relapsing pancreatitis and pancreatic cancer and in controls and were 402 +/- 69, 75 +/- 161, and 403 +/- 99 mm pancreatic juice, respectively. Peak secretory flow rates and pressures measured in controls during constant administration of secretin were similar to those measured when secretin was administered as a bolus.