title: Nicotinic acid timed to feeding reverses tissue lipid accumulation and improves glucose control in obese Zucker rats[S].
abstract: Nicotinic acid (NiAc) is a potent inhibitor of lipolysis, acutely reducing plasma free fatty acid (FFA) concentrations. However, a major FFA rebound is seen during rapid NiAc washout, and sustained exposure is associated with tolerance development, with FFAs returning to pretreatment levels. Our aim was to find a rational NiAc dosing regimen that preserves FFA lowering, sufficient to reverse nonadipose tissue lipid accumulation and improve metabolic control, in obese Zucker rats. We compared feeding-period versus fasting-period NiAc dosing for 5 days: 12 h subcutaneous infusion (programmable, implantable mini-pumps) terminated by gradual withdrawal. It was found that NiAc timed to feeding decreased triglycerides in liver (-47%; P < 0.01) and heart (-38%; P < 0.05) and reduced plasma fructosamine versus vehicle. During oral glucose tolerance test, plasma FFA levels were reduced with amelioration of hyperglycemia and hypertriglyceridemia. Furthermore, timing NiAc to feeding resulted in a general downregulation of de novo lipogenesis (DNL) genes in liver. By contrast, NiAc timed to fasting did not reduce tissue lipids, ameliorate glucose intolerance or dyslipidemia, or alter hepatic DNL genes. In conclusion, NiAc dosing regimen has a major impact on metabolic control in obese Zucker rats. Specifically, a well-defined NiAc exposure, timed to feeding periods, profoundly improves the metabolic phenotype of this animal model.
authors.affiliation: Division of Pharmacology and Toxicology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden tobias.kroon@astrazeneca.com.|AstraZeneca R&D, CVMD iMed, Gothenburg, Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kroon
authors.affiliation: AstraZeneca R&D, CVMD iMed, Gothenburg, Sweden.
authors.forename: Tania
authors.initials: T
authors.lastname: Baccega
authors.affiliation: AstraZeneca R&D, CVMD iMed, Gothenburg, Sweden.
authors.forename: Arne
authors.initials: A
authors.lastname: Olsén
authors.affiliation: Division of Pharmacology and Toxicology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Gabrielsson
authors.affiliation: AstraZeneca R&D, CVMD iMed, Gothenburg, Sweden.
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Oakes
mesh_terms: D000818:Animals; D001786:Blood Glucose; D005215:Fasting; D005227:Fatty Acids / Q000097:blood*; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000188:drug therapy; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000235:genetics; D050356:Lipid Metabolism / Q000187:drug effects*; D050155:Lipogenesis / Q000187:drug effects; D009525:Niacin / Q000008:administration & dosage*; D009765:Obesity / Q000097:blood / Q000188:drug therapy*; D051381:Rats; D011924:Rats, Zucker; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D014280:Triglycerides; D009525:Niacin; D005947:Glucose
keywords: GPR109A; adipose tissue; diabetes; drug therapy/hypolipidemic drugs; insulin; lipolysis and fatty acid metabolism; liver; niacin