ABSTRACT
BACKGROUND: Several studies have reported increased fat oxidation with diacylglycerol (DAG) oil consumption. However, the effects of long-term DAG oil consumption on energy metabolism remain to be investigated. OBJECTIVE: The objective of this study was to compare the effects of 14 days of either DAG or triacylglycerol (TAG) oil consumption on substrate oxidation, energy expenditure (EE) and dietary fat oxidation. DESIGN: Eight males and six females participated in this randomized, double-blind, crossover feeding study. Each patient consumed the 14-day controlled test diet containing either 10 g day(-1) of DAG or TAG oil for acclimatization before a respiratory chamber measurement, followed by a 2-week washout period between diet treatments. Substrate oxidation and EE were measured in the respiratory chamber at the end of each dietary treatment. The patients consumed test oil as 15% of total caloric intake in the respiratory chamber (mean test oil intake was 36.1+/-6.6 g day(-1)). RESULTS: Twenty-four hour fat oxidation was significantly greater with 14 days of DAG oil consumption compared with TAG oil consumption (78.6+/-19.6 and 72.6+/-14.9 g day(-1), respectively, P<0.05). There were no differences in body weight or body composition between diet treatments. Dietary fat oxidation was determined using the recovery rate of (13)CO(2) in breath, and was significantly enhanced with DAG oil consumption compared with TAG oil consumption, measured over 22 h after ingestion of (13)C-labelled triolein. Resting metabolic rate (RMR) was significantly greater with DAG oil consumption compared with TAG oil consumption (1766+/-337 and 1680+/-316 kcal day(-1), respectively, P<0.05). CONCLUSION: Consumption of DAG oil for 14 days stimulates both fat oxidation and RMR compared with TAG oil consumption, which may explain the greater loss of body weight and body fat with DAG oil consumption that has been observed in weight-loss studies.
Subject(s)
Adipose Tissue/drug effects , Dietary Fats/metabolism , Diglycerides/pharmacology , Energy Metabolism/drug effects , Plant Oils/pharmacology , Triglycerides/pharmacology , Adult , Breath Tests , Carbon Dioxide/chemistry , Cross-Over Studies , Diglycerides/administration & dosage , Double-Blind Method , Fatty Acids, Monounsaturated , Female , Food , Humans , Male , Middle Aged , Overweight/metabolism , Oxidation-Reduction , Plant Oils/administration & dosage , Rapeseed Oil , Safflower Oil/pharmacology , Soybean Oil/pharmacology , Tokyo , Triglycerides/administration & dosage , alpha-Linolenic Acid/pharmacologyABSTRACT
Monoclonal antibodies (mAbs) were raised against yeast mitochondrial nucleoids (mt-nucleoids). In an analysis by a combination of immunofluorescence microscopy and staining with 4',6-diamidino-2-phenylindole (DAPI), one of them, designated YMN-1, distinctly stained mt-nucleoids, which were visible as dots, in spheroplasts and in isolated mitochondria. However, staining of isolated mt-nucleoids was rather weak. YMN-1 mAb recognized a 48-kDa protein in immunoblots of both mitochondrial and mt-nucleoid proteins. The 48-kDa protein was a minor component of mt-nucleoid proteins and was separated from extract of both mitochondria and mt-nucleoids by immunoaffinity chromatography. The affinity-purified 48-kDa protein reassociated with mt-nucleoids when mixed with isolated mt-nucleoids, as monitored by immunofluorescence microscopy. The results suggest that a large amount of 48-kDa protein is associated with mt-nucleoids in vivo, and that lysis of mitochondria by the treatment with detergent releases a considerable amount of this protein from mt-nucleoids during the isolation of mt-nucleoids.
