Pancreatic Histological Changes Research Articles

Tissue Adhesives and the Pancreas

The aim of this study was to investigate biocompatibility and adhesive properties of 6 tissue adhesives available, when applied between the pancreas and jejunum in an experimental model. Portion of jejunum was glued on the pancreas in rats with 3 cyanoacrylate derivatives (Histoacryl, Dermabond, and Glubran 2), 2 human fibrin sealants (Tisseel Duo Quick and Quixil), and 1 albuminglutaraldehyde sealant (BioGlue). Pancreatic tissue specimens and blood samples were harvested 1, 3, 7, and 21 days after gluing for histological determination and amylase activity measurement. Pancreaticojejunal attachment created with adhesives underwent tensile strength measurement at each time point. Samples were also taken from unoperated rats and sham-operated rats. Exposure and sham groups both induced a similar increase in amylase activity on day 1 with normalization by day 3. Sham operation induced mild changes in the pancreas. Each tissue adhesive induced changes in pancreatic histology to the entire gland. Injurious effect was more severe with the 3 cyanoacrylates than with the 3 fibrin/semisynthetic glues. Histoacryl and Quixil induced lower tensile strength than the other adhesives. All of the tissue adhesives studied induced histological changes in the pancreas of which at least part might be considered harmful. The potentially harmful tissue effects of the preparations tested might compromise the use of these substances in pancreatic surgery.

Pancreatite aguda experimental induzida pela L-arginina: avaliação histológica e bioquímica

Excessive doses of basic amino acids such as L-arginine are able to injure the pancreas of rats. To describe and evaluate the biochemical and histological characteristics of acute pancreatitis in rats induced by L-arginine during the installation, development and repair stages of the pancreatic inflammatory process. MATERIAL AND METHODS - The study group consisted of 105 male Wistar rats. The rats in the experimental group (n = 70) received 500 mg/100 g of corporal weight L-arginine injection intraperitoneally. In the control group (n = 35), isotonic saline solution was injected. Ten rats in the experiment group and five in the control group were analyzed after 6, 12, 24, 48, and 72 hours, on the 7th and 14th days. During those times, blood samples were collected for laboratory testing and samples from the pancreas were collected for an optical microscopy analysis. From 12 to 24 hours after the injection of L-arginine, the amylase serum levels raised to their peak values when compared to the rats in the control group, decreasing gradually, reaching an equal level after the 48th hour and being significantly lower after 72 hours and 7 days. The enzymatic activity returned to its basal level after 14 days. The amylase values were normal in all the times evaluated in the control group. In optical microscopy, after the injection of L-arginine, a pancreatic architecture histologically preserved was observed after 6 hours, evidencing an important interstitial edema in 24 hours. After 48 hours, the acinar architecture was partially destroyed with focal cellular necrosis, reaching its maximum severity after 72 hours. On the 7th, the tissue necrosis and the edema had diminished, and the regeneration of the acinar architecture initiated. The pancreatic structural reconstruction could be observed after 14 days. Pancreatic histological changes were not found in the control group. - Experimental acute pancreatitis induced by L-arginine leads to pancreatic necrosis showing self-limited evolution with pancreas regeneration in 2 weeks.

Protective effect of central thyrotropin-releasing hormone analog on cerulein-induced acute pancreatitis in rats

Central neuropeptides play a role in many physiological functions through the autonomic nervous system. We have recently demonstrated that central injection of a thyrotropin-releasing hormone (TRH) analog increases pancreatic blood flow through vagal and nitric oxide-dependent pathways. In this study, the central effect of a TRH analog on experimental acute pancreatitis was investigated in rats. Acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg) at 1-h interval. Either stable TRH analog, RX 77368 (5–100 ng), or saline was injected intracisternally 15 min before the first cerulein injection under ether anesthesia. Serum amylase level was measured before and 5 h after the first cerulein injection. Pancreatic wet/dry weight ratio and histological changes were also evaluated. Intracisternal TRH analog inhibited cerulean-induced elevation of serum amylase level, increase in pancreatic wet/dry weight ratio and pancreatic histological changes, such as interstitial edema, inflammation and vacuolization. The pancreatic cytoprotection induced by central TRH analog was abolished by subdiaphragmatic vagotomy and N G-nitro- l-arginine-methyl ester ( l-NAME), but not by 6-hydroxydopamine (6-OHDA). Intravenous administration of the TRH analog did not influence cerulein-induced acute pancreatitis. These results indicate that the TRH analog acts in the central nervous system to protect against acute pancreatitis through vagal and nitric oxide-dependent pathways.

Pancreatic Injuries in Rats with Fecal Peritonitis: Protective Effect of a New Synthetic Protease Inhibitor, Sepinostat Mesilate (FUT-187)

To evaluate the effects of sepsis on the exocrine pancreas, we studied (1) serum amylase levels, pancreatic water and trypsin content; (2) pancreatic histological changes; (3) pancreatic subcellular distribution of lysosomal enzyme in the acinar cells; and (4) protective effects of a new synthetic protease inhibitor, FUT-187 against the pancreatic injuries in sepsis of rats induced by cecal ligation and puncture. Elevated serum amylase levels, increased pancreatic water and trypsin content, were observed in rats with fecal peritonitis induced by cecal ligation and puncture. Subcellular redistribution of lysosomal enzyme, cathepsin B, activity from the lysosomal fraction to the zymogen fraction was also observed. FUT-187 was found to significantly prevent these pancreatic injuries induced by fecal peritonitis. These results indicate that the exocrine pancreas is injured during sepsis, and that some unknown protease activities, which are present during sepsis and are susceptible to the inhibition of FUT-187, seem to play an important role in the pathogenesis of the pancreatic injuries induced by fecal peritonitis. These results also indicate the important pathological role of lysosomal enzymes in the pancreatic injuries induced by sepsis.

Rupture of small ducts and acini in the pancreas of the rat and guinea pig following major duct obstruction.

SummaryObstruction of the pancreatic duct system in the rat and the guinea pig leads to the rupture of pancreatic acini and ductules, consistently demonstrable by the periodic acid‐Schiff (PAS) technique.In the rat with pancreaticobiliary obstruction ruptured acini and ducts can also be revealed by interposing an ink‐filled tube between the hepatic and common ducts.A study has been made of the time course of pancreatic histological changes following pancreatic duct obstruction in the rat with and without common‐channel biliary obstruction. The addition of common‐channel biliary obstruction only slightly modified the picture causing haemorrhage in the wall of the common duct and more frequent and severe fat necrosis in the first 18 hr.Preliminary studies in the dog suggest that the periodic acid‐Schiff (PAS) technique may be useful in detecting ruptured acini in that species also.The occurrence and significance of increased mucus concentration within the obstructed pancreatic duct system is discussed.