Early inhibition of prostaglandin synthesis by n-3 fatty acids determinates histologic severity of necrotizing pancreatitis.

Objective: Previously, we observed decreased histopathological severity of acute necrotizing pancreatitis (ANP) by parenteral nutrition with n-3 fatty acids. Thus, we now sequentially analyzed the impact of n-3 fatty acids on prostaglandin and leukotriene synthesis in ANP.

Methods: One hundred ninety-eight Sprague-Dawley rats (11 groups, n = 18) underwent intraductal glycodesoxycholat instillation and 6-hour cerulein infusion. Afterward, saline was infused in groups 2, 4, 6, 8, and 10, whereas groups 3, 5, 7, 9, and 11 received infusion rich in n-3 fatty acids (Omegaven, Fresenius Kabi, Bad Homburg, Germany). Animals were killed after 6 (group 1), 10 (groups 2 and 3), 14 (groups 4 and 5), 18 (groups 6 and 7), 22 (groups 8 and 9), and 26 hours (groups 10 and 11). The pancreas was histopathologically examined, and the pancreatic eicosanoid metabolism (prostaglandin E2, prostaglandin F1alpha [PGF1alpha], and leukotrienes) and lipid peroxidation (thiobarbituric acid-reactive substance, superoxide dismutase, and glutathione peroxidase) were analyzed.

Results: Between the 14th and 26th hours, histopathologic scores (edema, inflammation, bleeding, and necrosis) were reduced in the n-3 fatty acid group compared with the corresponding saline group. Pancreatic prostaglandin E2 and PGF1alpha were decreased between the 10th and 18th hour by n-3 fatty acids; PGF1alpha was reduced after 26 hours compared with the corresponding saline group. Lipid peroxidation was decreased by n-3 fatty acids after 14 hours (thiobarbituric acid-reactive substance); however, there was no difference concerning lipid peroxidation protective enzymes (glutathione peroxidase and superoxide dismutase).

Conclusions: Parenteral therapy with n-3 fatty acids decreased histopathologic severity in ANP by early inhibition of prostaglandin (E2 and F1alpha) synthesis and reduction of lipid peroxidation.