Experimental Pancreatitis In Dogs Research Articles

Release of Dog Polymorphonuclear Leukocyte Cathepsin G, Normally and in Endotoxin and Pancreatitic Shock. Isolation and Partial Characterization of Dog Polymorphonuclear Leukocyte Cathepsin G

Dog polymorphonuclear leukocyte cathepsin G was isolated from a granule extract using a two-step procedure including affinity chromatography on a Trasylol-Sepharose gel and ion-exchange chromatography on a CM 52 column. 22 of the first 24 N-terminal amino acids were determined and showed 83% and 71% identity to those of human and rat cathepsin G, respectively. Total amino-acid composition demonstrated the basic nature of the protein. In an SDS/polyacrylamide-gel electrophoresis the protein showed an Mr of 29,400 compared to the Mr of 26,800 calculated from the total amino-acid composition. The enzyme was shown to form complexes with alpha 1 alpha 2-macroglobulin and alpha 1-proteinase inhibitor. A specific enzyme-linked immunosorbent assay was developed for the determination of cathepsin G/alpha 1-proteinase inhibitor complex in dog plasma and tissue fluids. The mean concentration of cathepsin G in normal dog plasma was determined to be 38 micrograms/l, measured as cathepsin G/alpha 1-proteinase inhibitor complex. When active dog cathepsin G was added to normal dog plasma in vitro, approximately 56% could be measured by the assay. Slow intravenous infusion of a lethal dose of endotoxin in dogs was followed by a marked drop in white blood cell count and thrombocytes and a simultaneous rapid increase in plasma cathepsin G concentration, reaching a maximum level of 150 micrograms/l. Bile-induced experimental pancreatitis in dogs was accompanied by successive increase in cathepsin G levels in plasma as well as in peritoneal exudates, reaching a maximum level of about 300 micrograms/l in plasma and 18 mg/l in the exudates during the late stages of disease.

Continuous peritoneal dialysis in acute experimental pancreatitis in dogs

In 27 beagle dogs, acute necrotizing pancreatitis was induced by retrograde injection of autologous bile and trypsin into the main pancreatic duct. Animals were randomly assigned to the following treatments: group 1--(9 dogs) aprotinin 600,000 KIU/d by i.v. route; group 2--(9 dogs) peritoneal dialysis for 6 d plus 500,000 KIU/L of aprotinin in the dialysate fluid; group 3--(9 dogs) peritoneal dialysis without aprotinin in the dialysate fluid. All dogs of the group 1 died within 16 h following the induction of pancreatitis and extensive necrotizing and hemorrhagic changes were seen in the pancreatic and peripancreatic areas. Six dogs of the group 2 survived and no necrotizing changes were observed 30 or 50 d after the induction of pancreatitis. Three dogs of the group 3 survived, but slight necrotizing lesions were found at the autopsy. The survival rate was higher in dogs with peritoneal lavage (p = 0.0129) or with peritoneal lavage plus aprotinin (p less than 0.0001) than in those receiving i.v. aprotinin, indicating that the latter treatment has no beneficiary effect on the course of acute pancreatitis.

Lysosomal-mitochondrial interrelationships in damage to the liver in acute experimental pancreatitis in dogs. Treatment with prostacyclin (PGI2).

In acute pancreatitis, damage to the liver is an important aspect of multiorgan failure. In 28 dogs (20 with bile-trypsin induced acute experimental pancreatitis (AEP], 'total' and 'free' activity of lysosomal hydrolases: beta-glucuronidase, cathepsins and acid phosphatase in mitochondrial and lysosomal subfraction of the liver were determined 12 h or 24 h after the induction of AEP. The respiratory control ratio with sodium succinate as a substrate, using Clarck's electrode and uncoupler-dependent ATP-ase activity in mitochondrial subfraction, was assayed. Groups of dogs were treated or pretreated with prostacyclin (PGI2), 20 ng.kg-1.min-1 i.v. for 12 or 13 h. The relative free activity of hydrolases was significantly elevated in untreated AEP after 12 h and was partially normalized in AEP after 24 h or after 12 h followed by treatment and pretreatment with PGI2. Respiratory control ratio was twice lower than normal in AEP after 12 h and partially normalized after 24 h post PGI2 treatment. The relative free activity of lysosomal hydrolases was highly negatively correlated with respiratory control ratio. It was concluded, that during AEP in dogs the function of liver mitochondria and lysosomal stability are impaired. The significant correlation found between the mitochondrial and lysosomal lesions points to lysosomal-mitochondrial interactions in liver damage in AEP. Prostacyclin in the investigated dose partially prevents the mitochondrial and lysosomal lesions in liver in this disease.

The enzymatic studies of the liver in acute experimental pancreatitis in dogs treated with prostacyclin (PGI 2)

The liver affection in acute experimental pancreatitis (AEP) could be reflected by changes of enzymatic activity in the liver and in serum. The histoenzymatic studies of the liver of dogs with AEP of different severity and time of duration induced according to Elliott's method were performed and the constellation of serum enzymatic activities considering treatment with prostacyclin was estimated. The histoenzymatic reactions on succinic dehydrogenase, lactic dehydrogenase and alkaline phosphatase were depressed with progression of time and severity of AEP. In contrast, the reaction on acid phosphatase was augmented at the same time. Serum AspAT, AlAT and alkaline phosphatase were augmented in the later phase of AEP, but acid phosphatase and beta-glucuronidase were not significantly changed. The treatment with PGI2 limited both histoenzymatic reactions and alterations of serum enzymatic activities. These results support the significance of changes in enzymatic activities in the course of liver reaction on pancreatogenic noxa during acute pancreatitis, and suggest the protective effect of PGI2 against liver injury in this disease.

Modifications induced in the flow and composition of the lymph of the thoracic duct by experimental pancreatitis in dogs

Modifications induced in the flow and composition of the lymph of the thoracic duct by experimental pancreatitis in dogs

Ultrastructure of liver in acute experimental pancreatitis in dogs treated with prostacyclin

The ultrastructure of the liver was studied in 3 groups of dogs (5 in each) with acute experimental pancreatitis (AEP) induced by injection of bile-trypsin mixture into the pancreatic duct. Experiments were terminated after 12 h. In the group of untreated animals, severe degeneration of mitochondria, extensive autophagocytosis, hyperactivity of Kupffer cells, depletion of glycogen granules, dilatation of endoplasmic spaces and vacuolisation of cytoplasm were found. In the group treated with prostacyclin PGI2 (20 ng/kg/min) in continuous i.v. infusion for 12 h, ultrastructural alterations were less advanced. Even better results were obtained in the group additionally pretreated for 1 h with the same rate of prostacyclin infusion. The results indicate a protective effect of prostacyclin against damage to the liver in the course of AEP.

The ultrastructure of the liver in acute experimental pancreatitis in dogs

The ultrastructure of the liver in acute experimental pancreatitis (AEP) in 18 dogs in three groups was investigated after 6, 12 and 24 h of the pathological process. AEP was induced by injection of an incubated mixture of bile and trypsin into the pancreatic duct. Swelling of mitochondria, depletion of glycogen, formation of autophagosomes more pronounced in later stages of AEP were evident. Complete destruction of some hepatocytes after 24 h was observed. Dilatation of Disse's spaces, activation of Kupffer cells and degranulation of mastocytes especially after 24 h were stated. Ultrastructural changes in the liver were present in 100% of the material. The severity of liver pathology was parallel to the intensity of pancreatic necrosis. The crucial stage of the damage to the liver during AEP seems to be the impairment of mitochondria.

The Renal Lysosomes in Acute Experimental Pancreatitis in Dogs Treated with Prostacyclin (PGI 2)

The inflammatory process in pancreas affects the function and structure of kidneys both by enzymatic toxemia and impairment of the renal circulation. In this study the stability of renal lysosomes in AEP in dogs treated with cytoprotective agent PGI2 was investigated. AEP was induced by injection of the bile and trypsin into the pancreatic duct; experiments were terminated after 12 hours. In lysosomal enriched subfraction of the kidney cortex (sedimenting in 15 000 x g) in untreated group (N = 5) relative free activity (r.f.a.) of cathepsins (Cs), acid phosphatase (APh) and beta-glucuronidase (BG) increased to 51,67 and 62% respectively, whereas in healthy dogs (N = 6) these activities were 20,38 and 25%. In dogs (N = 6) treated with PGI2 at the dose of 20 ng/kg/min. during 12 hrs, the r.f.a. of Cs, APh and BG was 18,40 and 49%, whereas in dogs (N = 5) additionally pretreated during 1 hr before induction of AEP with the same dose of PGI2, its values achieved 19,40 and 47% respectively. Our results suggest the stabilizing effect of PGI2 on kidney lysosomes damaged in acute experimental pancreatitis in dog. As possible mechanisms of prostacyclin action are discussed: limitation of necrotic process in the pancreas; improvement of renal haemodynamics; direct cytoprotective effect on the kidney.

Pathophysiology of acute pancreatitis: Evaluation of the effect and mode of action of steroids in experimental pancreatitis in dogs

Three experiments were performed to evaluate the effects and hemodynamic changes brought about by steroids in experimental pancreatitis in dogs. The results show (1) a significant improval in survival in steroid-treated groups, (2) no difference in cardiac output or mean blood pressure between groups, (3) a decrease in relative pancreatic arterial blood flow in the untreated animals, and (4) an increase in arterial flow to the pancreas after steroid therapy. The experiments suggest that the reversal of reduced pancreatic flow may be important in improving the prognosis.

Pathophysiology of acute pancreatitis: Evaluation of the effects and mode of action of indomethacin in experimental pancreatitis in dogs

Prostaglandins are known to affect vascular flow and the inflammatory response. Since acute pancreatitis involves both of these phenomena, we undertook studies using anesthetized mongrel dogs to investigate changes in blood pressure, cardiac output and pancreatic arterial flow for 6 hr in both normal animals (10 dogs) and following induction of acute pancreatitis (15 dogs). Indomethacin (5 mg/kg), which inhibits synthesis of prostaglandins, was then injected intravenously, and the animals were subsequently monitored for 2 hr. Results showed: (1) A significant fall in pancreatic arterial flow, relative to cardiac output, over the first 6 hr of the disease in the acute pancreatitis animals ( P < 0.001). (2) A further significant decrease in relative pancreatic arterial flow following indomethacin in these animals ( P < 0.001). A similar reduction in pancreatic arterial flow was observed following indomethacin administration in the control animals ( P < 0.001). Conclusions: (1) Relative pancreatic arterial flow falls during experimental acute pancreatitis. (2) Indomethacin reduces both basal and compromised pancreatic arterial flow in the anesthetized dog; this suggests that prostaglandins may participate in the maintainance of basal acid-compromised pancreatic blood flow in the anesthetized dog.

The functional and ultrastructural changes of hepatic mitochondria in acute experimental pancreatitis in dogs treated with prostacyclin

Acute pancreatitis affects the subcellular status of the liver both by enzymatic toxemia and by the impairment of the protective function exerted by a normal pancreas on the liver. The aim of this study was to investigate the effect of the cytoprotective agent prostacyclin (PGI 2 ) on hepatic mitochondria during acute experimental pancreatitis (AEP) in dogs. AEP was induced by the injection of a bile and trypsin mixture into the pancreatic duct, and experiments were terminated after 12 hrs with the exception of dogs with AEP 24 hrs (N = 5). The hepatic mitochondria from the group with AEP 12 hrs without treatment (N = 5) showed a significant impairment of succinate oxidation in St. 3 (with ADP) to 20.1 nanoatoms O×min −1 × mg −1 of mitochondrial protein in comparison to healthy dogs (N = 4) −37.6 units. The respiratory control ratio (RCR) in the former group was half as great as in the control group (1.56 and 3.13 respectively). The ADP: 0 ratio in this group was impossible to calculate. DNP-stimulated ATP-ase activity was lowered to 50.6 nM Pi min −1 mg −1 of protein in comparison to the healthy animals (642.7 units). In dogs AEP 12 hrs treated with PGI 2 in the dose of 20 ng/kg · min for 12 hrs (N = 5) and in the group additionally pretreated with PGI 2 for 1 hr before AEP (N = 5), the respective values of succinate oxidation in St. 3 were 22.2 and 26.5 units; RCR with ADP 2.05 and 2.07; ADP: O ratio 1.10 and 1.19 (in healthy dogs ADP: O = 1.90). DNP-stimulated ATP-ase activity was also augmented in comparison with the untreated group, 94.0 and 125.6 units, respectively. In the group with AEP 12 hrs without treatment, the ultrastructural examination of the liver showed severely damaged, mitochondria with swelling, destruction of limiting membranes and cristae. In the group with AEP 24 hrs without treatment the functional and morphological picture of mitochondria was improved in comparison to AEP 12 hrs and was comparable to treated groups. Prostacyclin in investigated dosage exerts a protective effect on hepatic mitochondria, damaged during acute experimental pancreatitis in dogs.

The effect of heparin on lysosomes of the dog pancreas during acute experimental pancreatitis

In 12 dogs with acute experimental pancreatitis (AEP) and 6 control animals the "free", "latent" and "total" activity of acid phosphatase, beta-glucuronidase and cathepsins in whole homogenates of the pancreas, in a lysosomal-enriched subfraction and the supernatant of pancreatic tissue was estimated. AEP was induced by injection of bile salts and thrombin solution into the pancreatic duct. In 6 dogs the protection with heparin (1.5 mg/kg/body weight) immediately after producing AEP was applied. In AEP without any protection the free activity of hydrolases in the whole homogenate (80--90%) and in the lysosomal enriched subfraction (75--90%) was higher than in the controls (60--70% and 55--75% respectively), suggesting an augmented lysosomal fragility during the course of AEP. Heparin depressed the free activity of hydrolases to 60--80% in whole homogenates, and 64--75% in the lysosomal enriched subfraction. The release of cathepsins during incubation of the lysosomal-enriched subfraction in acidic medium was lower in the group with heparin treatment. The data obtained suggest the stabilising effect of heparin on the lysosomes of the pancreas during acute experimental pancreatitis in dogs.

Hypotension and release of kinin-forming enzyme into ascitic fluid exudate during experimental pancreatitis in dogs.

SATAKE, KATSUSUKE M.D.; ROZMANITH, JOLAN S. PhD.; APPERT, HUBERT E. PhD.; CARBALLO, JORGE M.S.; HOWARD, JOHN M. M.D. Author Information

Arterial infusion of antienzymes in the treatment of experimental pancreatitis.

Direct arterial infusion of high doses of Trasylol results in a dramatic decrease in mortality rate in experimental pancreatitis in dogs.

Peritoneal lavage in experimental pancreatitis in dogs

Peritoneal lavage in experimental pancreatitis under the conditions of this study seems to offer some protection. While the mortality between animals with and without lavage supports this thesis, the appearance of the animals twenty-four hours after pancreatitis was even more striking. Chemistry determinations have not allowed any conclusions concerning the severity of the induced pancreatitis nor its probable lethality. Studies on the peritoneal fluid show it to be very similar to serum except in protein content. The protein is an albumin-like substance but its characteristics are not yet defined. The question arises as to the possible role of this protein in the toxicity of experimental pancreatitis.

Results of pathomorphologic studies on therapeutic experiments with enzyme inhibitors in experimental pancreatitis in dogs

Ergebnisse morphologischer und klinischer Untersuchungen an 80 Hunden, bei denen durch verschiedene Modifikationen eines Standardverfahrens eine experimentelle akute Pankreatitis erzeugt worden war, werden mitgeteilt. Morphologisch lassen sich im wesentlichen zwei Typen der Pankreatitis unterscheiden: Wahrend Zisatz von Calcium++-Ionen die vascularen Erscheinungen der „Taurocholatpankreatitis” verstarkt, verwischt die Verabreichung von Sekretstimulantien eher das typische Bild der „Olpankreatitis”. Der Nachweis einer protektiven Wirkung des Proteinase-Inhibitors Trasylol wird durch Limitierung nekrotischer Herde im Pankreas, eine deutlich geringere Beeinflussung des Elektrolythaushaltes von Calcium und anorganischem Phosphat im Serum, sowie durch die Herabsetzung der Mortalitat erbracht.

Hypothermia in acute hemorrhagic pancreatitis. Experimental study and clinical trial.

The mortality in acute hemorrhagic pancreatitis remains high despite all therapeutic measures and much experimental work. Theoretically it would seem that any measure tending to suppress the activity of the pancreas would aid in the management of this disease. Wangensteen and his co-workers 1 used intragastric cooling to control massive upper gastrointestinal tract bleeding and noted that the gastric secretory activity was depressed. More recently, Nabseth 2 reported questionable benefits from the use of intragastric cooling in the management of acute hemorrhagic pancreatitis. It occurred to us that pancreatic activity might perhaps be effectively reduced by the induction of total body hypothermia. Accordingly, a laboratory experiment was undertaken. Although experimental pancreatitis in dogs may not be identical with the disease in man, the physiologic defects produced are identical, and treatment which helps one usually helps the other. Experimental Study Method Acute hemorrhagic pancreatitis was surgically induced in 40 mongrel dogs

Serum Lipids in Acute Pancreatitis

Lactescence of the serum in acute pancreatitis, supposedly a rare manifestation of this disorder, was first reported in 1865.1 More recently, the increased incidence of relapsing pancreatitis in persons with idiopathic hyperlipemia has been stressed.2 6 The occurrence of elevated serum lipid levels in experimental pancreatitis in the dog was reported in 1929.7 Systematic studies performed in this laboratory demonstrated elevations of all serum lipid fractions in experimental acute pancreatitis in rabbits and dogs.8 It therefore appears that transient lipemia may accompany acute pancreatitis and that acute pancreatitis may be a complication of idiopathic hyperlipemia. Diabetic acidosis, if present, may contribute to the elevation of circulating lipoids. 9 . 10 It seemed profitable to review the records of patients with acute pancreatitis seen at the Mount Sinai Hospital during the past 22 years, with special emphasis on those in whom serum lipid determinations were performed. A smaller group of six patients, observed during the past five years, in whom serial determinations of serum lipids had been performed, are presented in detail. Serum cholesterol was determined by the Sperry-Schoenheimer method, phospholipids by the Sperry modification of the FiskeSubbaRow method, and total lipids by the Bloor method. Serum amylase was determined by the method of Somogyi (normal range 80 to 180 units per 100 ml). Selection of pat1·ents. One hundred and three patients, hospitalized between the years 1936 and 1957, were selected for review. The diagnosis of acute pancreatitis was established in 65 patients; by surgical laparotomy in 47 persons and by autopsy in 18 (proved cases). The diagnosis in the remaining 38 patients was based on clinical, laboratory, and roentgenologic findings (presumptive cases). Patients with chronic