Zonation of acetate labeling across the liver: implications for studies of lipogenesis by MIDA
| Autor: | Michelle A. Puchowicz, Ilya R. Bederman, Blandine Comte, Dawei Yang, France David, Eric Stone, Kareem Jabbour, David H. Wasserman, Henri Brunengraber |
|---|---|
| Přispěvatelé: | Case Western Reserve University [Cleveland] |
| Rok vydání: | 1999 |
| Předmět: |
Cholesterol synthesis
Blood Glucose Male medicine.medical_specialty Physiology Endocrinology Diabetes and Metabolism Biology Acetates Hepatic Veins Mass Spectrometry 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Dogs Hepatic Artery Biosynthesis Acetyl Coenzyme A Physiology (medical) Internal medicine medicine Animals [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Fatty acid synthesis 030304 developmental biology 0303 health sciences Carbon Isotopes Cholesterol Portal Vein Fatty Acids Metabolism Butyrates Endocrinology chemistry Biochemistry Liver 030220 oncology & carcinogenesis Isotopomer distribution Hyperglycemia Lipogenesis Female Propionates |
| Zdroj: | AJP-Endocrinology and Metabolism AJP-Endocrinology and Metabolism, American Physiological Society, 1999, 277 (6), pp.E1022-E1027. ⟨10.1152/ajpendo.1999.277.6.E1022⟩ |
| ISSN: | 0002-9513 0193-1849 1522-1555 |
| DOI: | 10.1152/ajpendo.1999.277.6.E1022⟩ |
| Popis: | Measurement of fractional lipogenesis by mass isotopomer distribution analysis (MIDA) of fatty acids or cholesterol labeled from [13C]acetate assumes constant enrichment of lipogenic acetyl-CoA in all hepatocytes. This would not be the case if uptake and release of acetate by the liver resulted in transhepatic gradients of acetyl-CoA enrichment. Conscious dogs, prefitted with transhepatic catheters, were infused with glucose and [1,2-13C2]acetate. Stable concentrations and enrichments of acetate were measured in artery (17 μM, 36%), portal vein (61 μM, 5.4%), and hepatic vein (17 μM, 1.0%) and were computed for mixed blood entering the liver (53 μM, 7.4%). We also measured balances of propionate and butyrate across gut and liver. All gut release of propionate and butyrate is taken up by the liver. The threefold decrease in acetate concentration and the sevenfold decrease in acetate enrichment across the liver strongly suggest that the enrichment of lipogenic acetyl-CoA decreases across the liver. Thus fractional hepatic lipogenesis measured in vivo by MIDA may be underestimated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|