title: Effect of substrate interactions on in vitro fatty acid synthesis in adipose tissue of normal and genetically obese mice.
abstract: Fatty acid synthesis was measured in vitro in pieces of adipose tissue from lean and obese-hyperglycaemic (ob/ob) mice, using 14C-glucose or 14C-lactate and 3H2O to obtain absolute rates of total fatty acid synthesis. In the presence of lipoprotein-triglyceride (2.5 mumol/l) metabolic interaction occurred which decreased glucose incorporation into fatty acids by 30% in lean mouse tissue, but not in obese mouse tissue. In the absence of added insulin, the contribution of glucose to total fatty acid synthesis was 69% in obese mouse tissue, significantly lower than the value of 87% obtained in lean mouse tissue. Insulin increased the contribution of glucose to total synthesis in both lean and obese mouse tissues, although the value in obese mouse tissue (83%) remained lower than the value in lean mouse tissue (100%). Lactate was not a major precursor for fatty acid synthesis. When both lactate (2 mmol/l) and glucose (15 mmol/l) were present, the contribution of lactate to total fatty acid synthesis was not increased in obese mouse tissue, suggesting that even in the presence of insulin, about 30% of the carbon was provided by intracellular precursors.
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D005227:Fatty Acids / Q000096:biosynthesis*; D005260:Female; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D007773:Lactates / Q000378:metabolism; D008074:Lipoproteins / Q000378:metabolism; D051379:Mice; D008820:Mice, Obese; D009765:Obesity / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D007328:Insulin; D007773:Lactates; D008074:Lipoproteins; D005947:Glucose