trypsinogen and Choline-Deficiency

Inappropriate extraluminal activation of trypsin is assumed to play a part in the pathogenesis of acute pancreatitis (AP), but proof has been elusive because active trypsin is transient and difficult to measure. We have previously shown increased levels of trypsinogen activation peptides (TAP), a direct measure of trypsin activation, to correlate with severity of AP, tissue necrosis, and survival in a rodent model induced by cerulein hyperstimulation and bile salt infusion. The present study seeks to show that increased trypsinogen activation also characterizes three other models of experimental AP in rodents to give credence to the generality of the phenomenon and to its potential relevance to human AP.. Experimental AP was induced in mice by a choline-deficient diet supplemented with ethionine and in rats by creation of a closed duodenal loop or by ligation of the biliopancreatic duct plus physiologic stimulation. TAP were quantified by an immunoassay in tissue and plasma at various time points after onset of AP.. In the group with choline-deficient diet supplemented with ethionine a significant increase in tissue and plasma TAP was found at 48 and 72 hours, respectively. In the group with closed duodenal loop significant TAP elevations were found in plasma as early as 6 hours and in the group with ligation of the biliopancreatic duct plus physiologic stimulation at 24 hours.. These experiments provide further evidence that extraluminal protease activation is a pathophysiologic event common to the evolution of various models of experimental acute pancreatitis and therefore increase the likelihood that this phenomenon is important in the human disease as well.

Topics: Acute Disease; Animals; Choline Deficiency; Diet; Disease Models, Animal; Duodenum; Enzyme Activation; Ethionine; Female; Ligation; Male; Mice; Necrosis; Oligopeptides; Pancreas; Pancreatic Ducts; Pancreatitis; Rats; Trypsinogen

A study on the effect of zinc feeding on the survival rate as well as the levels of trypsinogen, alpha 2-macroglobulin, zinc, calcium, and magnesium in the plasma, pancreata, and livers of BALB/c mice fed a choline-deficient diet supplemented with 0.5% DL-ethionine (CDE diet) was undertaken. Feeding them a zinc-excess diet significantly increased the survival rate of mice with pancreatitis induced by CDE diet feeding. Trypsinogen concentrations in plasma and pancreas increased in mice fed a CDE diet and further increased in mice fed a zinc-deficient diet. The plasma alpha 2-macroglobulin levels in mice fed a zinc-deficient diet decreased compared to those fed a zinc-adequate or a zinc-excess diet. In mice with pancreatitis, zinc and calcium concentrations of pancreata increased and magnesium concentrations decreased compared to those of normal controls. The calcium concentrations in both livers and pancreata increased, but magnesium concentrations in these tissues decreased. These results suggest that altered mineral metabolism in the pancreas may have contributed to the pathophysiology of the mice with acute pancreatitis and that zinc supplementation in the diet may be therapeutic for pancreatitis.

Topics: Acute Disease; alpha-Macroglobulins; Animals; Calcium; Choline Deficiency; Diet; Female; Magnesium; Male; Mice; Mice, Inbred BALB C; Pancreatitis; Survival Rate; Trypsinogen; Zinc

Topics: Acute Disease; Animals; Ceruletide; Choline Deficiency; Disease Models, Animal; Duodenum; Enzymes; Ethionine; Humans; Lysosomes; Pancreas; Pancreatic Ducts; Pancreatitis; Trypsin; Trypsinogen

Acute hemorrhagic pancreatic necrosis (AHPN) is induced in young female mice fed fo 4 days a choline-deficient diet containing diet 0.5% DL-ethionine (CDE). Contrary to females, male mice do not develop AHPN when fed the same diet. For determination of whether estrogens are involved in the induction of AHPN, estradiol-treated male mice were fed the CDE diet. In such estrogen-treated male mice, the mortality rate, incidence of AHPN, and alterations in biochemical parameters of the pancreas and of serum were similar to those induced by the CDE diet in females.

Topics: Acute Disease; Amylases; Animals; Blood Proteins; Cathepsin B; Cathepsins; Choline Deficiency; Diet; Estradiol; Female; Male; Mice; Necrosis; Pancreas; Pancreatitis; Trypsin; Trypsinogen

Prostaglandins have been noted to have a "protective" effect against gastrointestinal mucosal injury induced by a wide variety of agents although possible protective effects of prostaglandins on injury to other tissues have not been reported. We have tested the effect of prostaglandin E2 (PGE2) on acute experimental pancreatitis induced by feeding young female mice a choline-deficient ethionine-supplemented (CDE) diet for 24 hr. Administration of 0.05--0.20 microgram PGE2/g body wt 1 hr before and 4 hr after institution of the CDE diet lowered the mortality rate of diet-induced pancreatitis from 56% to 31%. Larger and smaller doses of PGE2 were without effect. Administration of PGE2 (0.10 microgram/g body weight) diminished the rise in in-vitro LDH discharge and the increase in "free" Cathepsin D activity which occur during diet-induced pancreatitis. Similarly, PGE2 (0.10 microgram/g body wt) diminished the magnitude of the increase in in-vitro protein discharge and the elevated concentrations of trypsinogen and chymotrypsinogen in pancreas fragments taken from mice given the CDE diet. These findings indicate the PGE2 has a protective effect against CDE diet-induced acute experimental pancreatitis. The Cathespin D and LDH changes noted during CDE diet-induced pancreatitis suggest that this diet may decrease membrane integrity and thus allow these enzymes to leak out of the lysosomes and acinar cell, respectively, during pancreatitis. Although the basis for the protective effect of PGE2 remains unclear, our observations suggest that the prostaglandin may act to reduce the alteration in membrane integrity which occurs during CDE-diet induced pancreatitis.

Topics: Amylases; Animals; Cathepsins; Choline Deficiency; Chymotrypsinogen; Diet; Ethionine; Female; In Vitro Techniques; L-Lactate Dehydrogenase; Mice; Pancreatitis; Prostaglandins E; Proteins; Trypsinogen

The earliest changes noted during the evolution of pancreatitis induced by feeding mice a choline-deficient ethionine-supplemented (CDE) diet are an increase in the number of zymogen granules in pancreatic acinar cells and an increase in digestive enzyme content of the pancreas. We have studied the processes of protein and digestive enzyme synthesis and discharge at varying times after institution of the CDE diet, a choline-deficient diet (CD), and a diet containing ethionine but not choline-deficient (E). Both the CDE and E diets increased digestive enzyme content within 12 h of their institution. Both the CDE and E diets reduced the rate of protein and amylase synthesis and caused a marked reduction in the rate of protein and amylase discharge from the pancreas. These changes were greatest and were noted earliest in the CDE diet group. A marked reduction in secretagogue-induced in vivo and in vitro amylase discharge followed ingestion of either the CDE or E diet. These studies indicate that the increased pancreatic content of digestive enzymes noted after ingestion of the CDE and E diets results from an ethionine-induced decrease in the rat of digestive enzyme discharge. This phenomenon is enhanced by simultaneous choline deficiency. Subsequent intrapancreatic activation of zymogens may couple these changes in enzyme content to the development of hemorrhagic pancreatitis.

Topics: Amylases; Animals; Cholecystokinin; Choline; Choline Deficiency; Chymotrypsinogen; Ethionine; Female; Mice; Pancreas; Trypsinogen