Effect of gastric acid suppressants on human gastric motility Reply
Year: 1999
Type: letter
Abstract: Phospholipase A 2 and acute pancreatitis in rats EDITOR,-Phospholipase A 2 (PLA 2 ) is an enzyme that cleaves fatty acids from phospholipids, leading to the generation of inflammatory eicosanoids. 1 The group II isoenzyme of phospholipase A 2 (PLA 2 -II) is raised in peripheral blood during various inflammatory states. 2 PLA 2 is induced in vitro and in vivo by the classic acute phase cytokine interleukin 6. 3 4 Therefore PLA 2 -II can be regarded as an acute phase protein.With great interest we read the well designed study of Furue et al (Gut 1997;41:826-31) who could clearly show that most PLA 2 activity during sodium deoxycholate induced acute pancreatitis in rats is due to the group II isoenzyme.Furue and colleagues suggested that the liver is the main source of this enzyme in their experiments because Nevalainen and coworkers 5 and Crowl and coworkers 3 described PLA 2 -II activity in human hepatocytes.We agree with the suggestion of Furue et al that PLA 2 -II is produced in human hepatocytes like classic acute phase proteins.This was also demonstrated by our group, 6 but we think that the extrapolation of these findings from human tissue to animal experiments, as done by Furue et al, requires some clarification.Hatch et al were able to show that liver macrophages and not hepatocytes were the main source of PLA 2 -II in rats during endotoxin induced acute phase reaction. 7As a consequence, liver macrophages but not hepatocytes could also be the main source of PLA 2 -II in the animal experiments presented by Furue and collaborators.Therefore an alternative pathogenetic mechanism leading to liver damage in experimental induced acute pancreatitis should be taken into account.Our alternative pathogenetic sequence is that PLA 2 -II released by liver macrophages attacks adjacent already damaged liver tissue, thus leading to complete destruction of hepatocytes with subsequent release of aminotransferases into the circulation, as shown by Furue et al.In conclusion, we agree that PLA 2 -II could be an important mediator of liver failure in acute pancreatitis, but alternative pathomechanisms resulting from diVerent production sites should be discussed.
Source: Gut
Authors: M BORTOLOTTI, H P PARKMAN, R S FISHER
Institution: University of Bologna
Language: English
Subfield: Gastroenterology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W877122145