Plasma metabolomics reveal alterations of sphingo- and glycerophospholipid levels in non-diabetic carriers of the transcription factor 7-like 2 polymorphism rs7903146.

AIMS/HYPOTHESIS: Polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene have been shown to display a powerful association with type 2 diabetes. The aim of the present study was to evaluate metabolic alterations in carriers of a common TCF7L2 risk variant. METHODS: Seventeen non-diabetic subjects carrying the T risk allele at the rs7903146 TCF7L2 locus and 24 subjects carrying no risk allele were submitted to intravenous glucose tolerance test and euglycemic-hyperinsulinemic clamp. Plasma samples were analysed for concentrations of 163 metabolites through targeted mass spectrometry. RESULTS: TCF7L2 risk allele carriers had a reduced first-phase insulin response and normal insulin sensitivity. Under fasting conditions, carriers of TCF7L2 rs7903146 exhibited a non-significant increase of plasma sphingomyelins (SMs), phosphatidylcholines (PCs) and lysophosphatidylcholines (lysoPCs) species. A significant genotype effect was detected in response to challenge tests in 6 SMs (C16:0, C16:1, C18:0, C18:1, C24:0, C24:1), 5 hydroxy-SMs (C14:1, C16:1, C22:1, C22:2, C24:1), 4 lysoPCs (C14:0, C16:0, C16:1, C17:0), 3 diacyl-PCs (C28:1, C36:6, C40:4) and 4 long-chain acyl-alkyl-PCs (C40:2, C40:5, C44:5, C44:6). DISCUSSION: Plasma metabolomic profiling identified alterations of phospholipid metabolism in response to challenge tests in subjects with TCF7L2 rs7903146 genotype. This may reflect a genotype-mediated link to early metabolic abnormalities prior to the development of disturbed glucose tolerance.

Fish oil, but not soy bean or olive oil enriched infusion decreases histopathological severity of acute pancreatitis in rats without affecting eicosanoid synthesis.

Different dietary fatty acids affect eicosanoid metabolism in different ways, thus influencing the pro- and anti-inflammatory balance of prostaglandins and leukotrienes. Therefore, we analyzed the impact of [n-3], [n-6], and [n-9] fatty acids on eicosanoid metabolism and histopathology in acute pancreatitis in rats. Seventy-five male Sprague-Dawley rats were randomized into five groups (n = 15). Group 1 underwent only laparotomy, while in groups, 2-5 pancreatitis was induced. Groups 1 and 2 were then given saline infusion, groups 3-5 received fat emulsion (group 3: rich in [n-6], group 4: rich in [n-9], group 5: rich in [n-3] fatty acids) for another 18 h. Infusion rich in [n-3] fatty acids significantly decreased histopathological severity of pancreatitis, compared to all other groups. There was no difference concerning the concentrations of prostaglandins and leukotrienes between all groups. Parenteral infusion rich in [n-3] fatty acids reduced histopathological severity of acute pancreatitis in rats without changing eicosanoid metabolism at the endpoint.

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.

Effects of octreotide in acute hemorrhagic necrotizing pancreatitis in rats.

BACKGROUND AND AIM: Octreotide is considered to reduce exocrine pancreatic secretion in acute hemorrhagic necrotizing pancreatitis decreasing pancreatic autodigestion. The aim of this study was to determine whether octreotide also has antioxidative effects in acute pancreatitis. Additionally time and dose of application were of interest. METHOD: Ninety male Sprague-Dawley rats were randomized into six groups (n = 15). Group 1 underwent a laparotomy, and animals in groups 2-6 received intraductal glycodeoxycholic acid followed by intravenous cerulein. Groups 3 and 4 were injected with 0.5 mg octreotide, while groups 5 and 6 received continuous intravenous infusion of 0.05 mg octreotide/h for 10 h. Treatment was initiated 6 hours after induction of pancreatitis (IP) in groups 3 and 5, and 14 h after IP in groups 4 and 6. At 24 h after IP all animals were killed and each pancreas was analyzed histopathologically. In addition, levels of pancreatic lipid peroxidation protective enzymes glutathione-peroxidase (GSH-Px) and superoxide dismutase (SOD) as well as lipid peroxidation via thiobarbituric acid reactive substances (TBARS) were determined. RESULTS: Early bolus application of octreotide reduced severity of histopathological changes in acute pancreatitis and decreased lipid peroxidation in pancreatic tissue samples; however, late bolus application and continuous intravenous infusion did not influence pancreatitis or lipid peroxidation. CONCLUSION: Octreotide seems to have a dose- and time-dependent effect on histopathology and lipid peroxidation in a model of pancreatitis in rats.

Impact of taurolidin and octreotide on liver metastasis and lipid peroxidation after laparoscopy in chemical induced ductal pancreatic cancer.

BACKGROUND: There is controversial discussion whether metastasis initiated by laparoscopy with carbon dioxide might be prevented by instillation of taurolidin or radical scavengers like the somatostatin analogue Octreotide. Therefore we evaluated the effects of laparoscopic lavage with taurolidin and Octreotide on liver metastasis after staging laparoscopy in ductal pancreatic cancer. METHODS: In 60 Syrian hamsters pancreatic adenocarcinoma was induced by weekly subcutanous injection of 10 mg N-nitrosobis-2-oxopropylamin/kg body weight for 10 weeks. In the 16th week laparoscopic staging biopsy by use of carbon dioxide was performed. Finally animals underwent abdominal irrigation with saline (gr.1, n = 20), taurolidin (0.5%) (gr.2, n = 20) or Octreotide (gr.3, n = 20). In week 25 animals were sacrificed, pancreas and liver were analysed. RESULTS: Size of pancreatic carcinomas was decreased in the taurolidin gr. compared to the other two groups. Furthermore the number of liver metastasis per animal was reduced after lavage with taurolidin (2 +/- 2) and Octreotide (2.5 +/- 2) compared to saline irrigation (4 +/- 4) (p < 0.05). Additionally the incidence of port site metastases was significantly reduced in the taurolidin group. Activity of antioxidative enzyme superoxide dismutase (SOD) was increased while concentration of products of lipidperoxidation was decreased in non-metastatic liver after taurolidin irrigation compared to saline or Octreotide irrigation. CONCLUSIONS: Taurolidin irrigation during laparoscopy might be a new concept to reduce the number of liver metastasis and port site metastases in pancreatic cancer.