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- Nilsen, A.J., et al.
(author)
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Comparative hepatic gene expression profiling of rats treated with 1H,1H,2H,2H-heptadecafluorodecan-1-ol or with pentadecafluorooctanoic acid
- 2008
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In: Physiol. Genomics. - : American Physiological Society. ; 34, s. 285-303
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Journal article (peer-reviewed)abstract
- Pentadecafluorooctanoic acid is an established peroxisome proliferator. Little is known about effects of treatment with 1 H,1 H,2 H,2 H-heptadecafluorodecan-1-ol, which is metabolized to pentadecafluorooctanoic acid. We compared effects of various dosages (3, 10, or 25 mg/kg body wt) of each of these compounds on hepatic gene expression in rats with microarrays. Microarray data were validated by real-time RT-PCR. Expression data were also correlated with hepatic activities of selected enzymes and with hepatic levels of pentadecafluorooctanoic acid and 1 H,1 H,2 H,2 H-heptadecafluorodecan-1-ol. Pentadecafluorooctanoic acid caused the more powerful change in gene expression, in terms of both number of genes affected and extent of change in expression. Across the dosages used pentadecafluorooctanoic acid and 1 H,1 H,2 H,2 H-heptadecafluorodecan-1-ol caused significant ( P ≤ 0.05) changes in expression for 441 and 105 genes, respectively. With 1 H,1 H,2 H,2 H-heptadecafluorodecan-1-ol ∼38% of the 105 genes exhibited decreased expression with a dose of 25 mg/kg body wt, these genes also appearing less responsive to treatment at the lower dosages. Bioinformatic analysis suggested that these genes are associated with regulatory functions. With pentadecafluorooctanoic acid, increasing dosage up to 10 mg/kg body wt brought about progressive increase in expression of affected genes. Pathways analysis suggested similar effects of the two compounds on lipid and amino acid metabolism. Marked differences were also found, particularly with respect to effects on genes related to oxidative phosphorylation, oxidative metabolism, free radical scavenging, xenobiotic metabolism, and complement and coagulation cascades.
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| 2. |
- Rosenstock, J, et al.
(author)
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Effects of the DPP-4 Inhibitor Vildagliptin on Incretin Hormones, Islet Function, and Postprandial Glycemia in Subjects with Impaired Glucose Tolerance
- 2008
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In: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 31:1, s. 30-35
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Journal article (peer-reviewed)abstract
- Objective: This study was conducted to determine the effects of vildagliptin on incretin hormone levels, islet function, and postprandial glucose control in subjects with impaired glucose tolerance (IGT). Research Design and Methods: A 12-week double-blind, randomized, parallel-group study comparing vildagliptin (50 mg qd) and placebo was conducted in 179 subjects with IGT (2-h glucose= 9.1 mmol/l, A1C= 5.9%). Plasma levels of intact GLP-1 and GIP, glucose, insulin, C-peptide, and glucagon were measured during standard meal tests performed at baseline and Week 12. Insulin secretory rate (ISR) was estimated by C-peptide deconvolution. The between-group differences (vildagliptin - placebo) in the adjusted mean changes from baseline to endpoint in the total and incremental (Delta) AUC(0-2h) for these analytes were assessed by ANCOVA; glucose AUC(0-2h) was the primary outcome variable. Results: Relative to placebo, vildagliptin increased GLP-1 (DeltaAUC, +6.0+/-1.2 pmol/l*h, P<0.001) and GIP (DeltaAUC, +46.8+/-5.4 pmol/l*h, P<0.001) and decreased glucagon (DeltaAUC, -3.0 +/- 1.0 pmol/l*h, P=0.003). Although postprandial insulin levels were unaffected (DeltaAUC, +20.8+/-35.7 pmol/l*h, P=0.561), prandial glucose excursions were reduced (DeltaAUC, -1.0+/-0.3 mmol/l*h, P<0.001), representing approximately 30% decrease relative to placebo. Beta-cell function as assessed by the ISR AUC(0-2h)/glucose AUC(0-2h) was significantly increased (+6.4 +/- 2.0 pmol*min(-1)*m(-2)*mM(-1), P=0.002). Adverse event profiles were similar in the two treatment groups and no hypoglycemia was reported. Conclusions: The known effects of vildagliptin on incretin levels and islet function in type 2 diabetes were reproduced in subjects with IGT with a 32% reduction in postprandial glucose excursions and no evidence of hypoglycemia or weight gain.
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