21.   There are, however, some differences in the action of caerulein and platelet activating factor on the pancreas.

22.   When infiltrated by inflammatory cells, the mucosa is known to generate a variety of inflammatory lipidic mediators such as arachidonic acid metabolites and platelet activating factor.

23.   Platelet activating factor is a lipid mediator derived from membrane phospholipids and involving in hypersensitivity and inflammatory reactions.

24.   Lyso platelet activating factor was chemically acetylated into platelet activating factor, extracted in ethanol and measured as previously described.

25.   The amount of lyso platelet activating factor was calculated as the difference between the quantity of platelet activating factor measured after and before acetylation of the samples.

26.   The dried residues were then acetylated as described above and platelet activating factor was assayed.

27.   The amount of alkyl acyl glycerophosphocholine was calculated as the difference between the levels of platelet activating factor measured before and after alkaline hydrolysis and acetylation.

28.   The mucosal content of platelet activating factor was higher in inflamed than in non-inflamed mucosa, but no significant correlation was observed with the severity of mucosal inflammation.

29.   Ethanolic extraction is now a common method to extract platelet activating factor from various organs including biopsy specimens.

30.   So far, the cellular origin of platelet activating factor from colonic mucosa remains unclear.