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Johansen MØ, Afzal S, Vedel-Krogh S, Nielsen SF, Smith GD, Nordestgaard BG. From plasma triglycerides to triglyceride metabolism: effects on mortality in the Copenhagen General Population Study. Eur Heart J 2023; 44:4174-4182. [PMID: 37575001 DOI: 10.1093/eurheartj/ehad330] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 03/06/2023] [Accepted: 05/15/2023] [Indexed: 08/15/2023] Open
Abstract
AIMS It is unclear whether higher triglyceride metabolism per se contributes to mortality separate from elevated triglyceride-rich lipoproteins and body mass index. This study tested the hypotheses that higher triglyceride metabolism, measured as higher plasma glycerol and β-hydroxybutyrate, is associated with increased all-cause, cardiovascular, cancer, and other mortality. METHODS AND RESULTS This study included 30 000 individuals nested within 109 751 individuals from the Copenhagen General Population Study. During a median follow-up of 10.7 years, 9897 individuals died (2204 from cardiovascular, 3366 from cancer, and 2745 from other causes), while none were lost to follow-up. In individuals with glycerol >80 µmol/L (highest fourth) vs. individuals with glycerol <52 µmol/L (lowest fourth), the multivariable adjusted hazard ratio for all-cause mortality was 1.31 (95% confidence interval 1.22-1.40). In individuals with β-hydroxybutyrate >154 µmol/L (highest fourth) vs. individuals with β-hydroxybutyrate <91 µmol/L (lowest fourth), the multivariable adjusted hazard ratio for all-cause mortality was 1.18 (1.11-1.26). Corresponding values for higher plasma glycerol and β-hydroxybutyrate were 1.37 (1.18-1.59) and 1.18 (1.03-1.35) for cardiovascular mortality, 1.24 (1.11-1.39) and 1.16 (1.05-1.29) for cancer mortality, and 1.45 (1.28-1.66) and 1.23 (1.09-1.39) for other mortality, respectively. Results were robust to exclusion of first years of follow-up, to stratification for covariates including plasma triglycerides and body mass index, and to further adjustments. CONCLUSION This study observed an increased risk of all-cause, cardiovascular, cancer, and other mortality with higher triglyceride metabolism. This was not explained by higher plasma triglycerides and body mass index. The hypothesis studied in the present paper should be further validated by isotope flux studies.
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Affiliation(s)
- Mia Ø Johansen
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Elevator 7, 4th Floor, N5, Herlev DK-2730, Denmark
- The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Herlev DK-2730, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N DK-2200, Denmark
| | - Shoaib Afzal
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Elevator 7, 4th Floor, N5, Herlev DK-2730, Denmark
- The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Herlev DK-2730, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N DK-2200, Denmark
| | - Signe Vedel-Krogh
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Elevator 7, 4th Floor, N5, Herlev DK-2730, Denmark
- The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Herlev DK-2730, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N DK-2200, Denmark
| | - Sune F Nielsen
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Elevator 7, 4th Floor, N5, Herlev DK-2730, Denmark
- The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Herlev DK-2730, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N DK-2200, Denmark
| | - George Davey Smith
- MRC Integrative Epidemiology Unit (IEU), Bristol Medical School, University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Børge G Nordestgaard
- Department of Clinical Biochemistry, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Elevator 7, 4th Floor, N5, Herlev DK-2730, Denmark
- The Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Borgmester Ib Juuls Vej 73, Herlev DK-2730, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen N DK-2200, Denmark
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Joubert A, Joubert A, van der Merwe M, Norman J, Castel S, Denti P, Sliwa K, Maartens G, Sinxadi P, Wiesner L. Validation of a quantitative multiplex LC-MS/MS assay of carvedilol, enalaprilat, and perindoprilat in dried blood spots from heart failure patients and its cross validation with a plasma assay. J Mass Spectrom Adv Clin Lab 2022; 27:7-17. [PMID: 36568714 PMCID: PMC9772843 DOI: 10.1016/j.jmsacl.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
Introduction Adherence to medication is an important determinant of outcomes in chronic diseases like heart failure. Drug assays provide objective adherence biomarkers. Dried blood spots (DBS) are appealing samples for drug assays due to less demanding transportation and storage requirements. Objectives To analytically validate a LC-MS/MS method for the simultaneous quantification of carvedilol, enalaprilat, and perindoprilat in DBS and evaluate the feasibility of using the method as an adherence determining assay. To validate the assay further clinically by establishing correlation and agreement between plasma and DBS samples from a pharmacokinetic pilot study. Methods The method was validated over a concentration range of 1.00-200 ng/mL according to FDA guidelines. Adherence tracking ability of the assay was evaluated using a pharmacokinetic pilot study. Correlation and agreement were evaluated through Deming regression and Bland-Altman analysis, respectively. Results Accuracy, precision, selectivity, and sensitivity were proven with complete and reproducible extraction recovery at all concentrations tested. Stability of the analytes in the matrix and throughout sample processing was proven. The full range of concentrations of the pharmacokinetic pilot study could be quantified for enalaprilat, but not for carvedilol and perindoprilat. The difference between the observed and calculated plasma concentrations was less than 20 % of their mean for >67 % of samples for all analytes. Conclusions The assay is suitable as a screening tool for carvedilol and perindoprilat, while suitable as an adherence determining assay for enalaprilat. Equivalence between observed and predicted plasma concentrations proves DBS and plasma concentrations can be used interchangeably.
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Key Words
- ACE-I, Angiotensin-converting enzyme inhibitors
- ALQ, Above the Limit of Quantitation
- Adherence
- BD, Bidaily
- BMI, Body mass index
- CHF, Chronic Heart Failure
- CID, Collision-induced dissociation
- CV, Co-efficient of variation
- Carvedilol
- DBS, Dried Blood Spots
- Dried blood spots
- EMA, European Medicines Agency
- ESI, Electrospray ionization
- Enalaprilat
- HF, Heart Failure
- ISTD, Internal standard
- ITP, Initial testing procedure
- LC-MS/MS
- LC-MS/MS, Liquid Chromatography with tandem mass spectrometry
- LLOQ, lower limit of quantitation
- LOD, Limit of detection
- MRM, Multiple reaction monitoring
- NYHA FC, New York Heart Association Functional Classification
- OD, Once Daily
- Perindoprilat
- QC DIL, Quality control dilution
- QC LLOQ, Quality control lowest level of quantification
- QC, Quality Control
- QCH, Quality control high
- QCL, Quality control low
- QCM, Quality control medium
- S/N, signal-to-noise ratio
- SOP, Standard operating procedure
- ULOQ, upper limit of quantification
- VAMS, volumetric absorptive micro sampling
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Affiliation(s)
- Andre Joubert
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Anton Joubert
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Marthinus van der Merwe
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Jennifer Norman
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Sandra Castel
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Paolo Denti
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Karen Sliwa
- Cape Heart Institute, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa,Division of Cardiology, Department of Medicine, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa
| | - Gary Maartens
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Phumla Sinxadi
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa,Corresponding author.
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Zeng W, Yin X, Jiang Y, Jin L, Liang W. PPARα at the crossroad of metabolic-immune regulation in cancer. FEBS J 2022; 289:7726-7739. [PMID: 34480827 DOI: 10.1111/febs.16181] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/04/2021] [Accepted: 09/03/2021] [Indexed: 01/14/2023]
Abstract
Rewiring metabolism to sustain cell growth, division, and survival is the most prominent feature of cancer cells. In particular, dysregulated lipid metabolism in cancer has received accumulating interest, since lipid molecules serve as cell membrane structure components, secondary signaling messengers, and energy sources. Given the critical role of immune cells in host defense against cancer, recent studies have revealed that immune cells compete for nutrients with cancer cells in the tumor microenvironment and accordingly develop adaptive metabolic strategies for survival at the expense of compromised immune functions. Among these strategies, lipid metabolism reprogramming toward fatty acid oxidation is closely related to the immunosuppressive phenotype of tumor-infiltrated immune cells, including macrophages and dendritic cells. Therefore, it is important to understand the lipid-mediated crosstalk between cancer cells and immune cells in the tumor microenvironment. Peroxisome proliferator-activated receptors (PPARs) consist of a nuclear receptor family for lipid sensing, and one of the family members PPARα is responsible for fatty acid oxidation, energy homeostasis, and regulation of immune cell functions. In this review, we discuss the emerging role of PPARα-associated metabolic-immune regulation in tumor-infiltrated immune cells, and key metabolic events and pathways involved, as well as their influences on antitumor immunity.
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Affiliation(s)
- Wenfeng Zeng
- Protein and Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xiaozhe Yin
- Protein and Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,School of Medicine, Tsinghua University, Beijing, China
| | - Yunhan Jiang
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Lingtao Jin
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Wei Liang
- Protein and Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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Abe RJ, Abe JI, Nguyen MTH, Olmsted-Davis EA, Mamun A, Banerjee P, Cooke JP, Fang L, Pownall H, Le NT. Free Cholesterol Bioavailability and Atherosclerosis. Curr Atheroscler Rep 2022; 24:323-336. [PMID: 35332444 PMCID: PMC9050774 DOI: 10.1007/s11883-022-01011-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW As both a cholesterol acceptor and carrier in the reverse cholesterol transport (RCT) pathway, high-density lipoprotein (HDL) is putatively atheroprotective. However, current pharmacological therapies to increase plasma HDL cholesterol (HDL-c) concentration have paradoxically failed to prevent or reduce atherosclerosis and cardiovascular disease (CVD). Given that free cholesterol (FC) transfer between surfaces of lipoproteins and cells is reversible, excess plasma FC can be transferred to the cells of peripheral tissue sites resulting in atherosclerosis. Here, we summarize potential mechanisms contributing to this paradox and highlight the role of excess free cholesterol (FC) bioavailability in atherosclerosis vs. atheroprotection. RECENT FINDINGS Recent findings have established a complex relationship between HDL-c concentration and atherosclerosis. Systemic scavenger receptor class B type 1 (SR-B1) knock out (KO) mice exhibit with increased diet-induced atherosclerosis despite having an elevated plasma HDL-c concentration compared to wild type (WT) mice. The greater bioavailability of HDL-FC in SR-B1 vs. WT mice is associated with a higher FC content in multiple cell types and tissue sites. These results suggest that dysfunctional HDL with high FC bioavailability is atheroprone despite high HDL-c concentration. Past oversimplification of HDL-c involvement in cholesterol transport has led to the failures in HDL targeted therapy. Evidence suggests that FC-mediated functionality of HDL is of higher importance than its quantity; as a result, deciphering the regulatory mechanisms by which HDL-FC bioavailability can induce atherosclerosis can have far-reaching clinical implications.
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Affiliation(s)
- Rei J Abe
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Jun-Ichi Abe
- Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Minh T H Nguyen
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | | | - Abrar Mamun
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
| | - Priyanka Banerjee
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
| | - John P Cooke
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medicine, New York, NY, USA
| | - Longhou Fang
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medicine, New York, NY, USA
| | - Henry Pownall
- Weill Cornell Medicine, New York, NY, USA
- Center for Bioenergetics, Department of Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Nhat-Tu Le
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA.
- Weill Cornell Medicine, New York, NY, USA.
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Reproducibility of Targeted Lipidome Analyses (Lipidyzer) in Plasma and Erythrocytes over a 6-Week Period. Metabolites 2020; 11:metabo11010026. [PMID: 33396510 PMCID: PMC7823270 DOI: 10.3390/metabo11010026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/29/2020] [Accepted: 12/29/2020] [Indexed: 11/30/2022] Open
Abstract
It is essential to measure lipid biomarkers with a high reproducibility to prevent biased results. We compared the lipid composition and inter-day reproducibility of lipid measurements in plasma and erythrocytes. Samples from 42 individuals (77% women, mean age 65 years, mean body mass index (BMI) 27 kg/m2), obtained non-fasted at baseline and after 6 weeks, were used for quantification of up to 1000 lipid species across 13 lipid classes with the Lipidyzer platform. Intraclass correlation coefficients (ICCs) were calculated to investigate the variability of lipid concentrations between timepoints. The ICC distribution of lipids in plasma and erythrocytes were compared using Wilcoxon tests. After data processing, the analyses included 630 lipids in plasma and 286 in erythrocytes. From these, 230 lipids overlapped between sample types. In plasma, 78% of lipid measurements were reproduced well to excellently, compared to 37% in erythrocytes. The ICC score distribution in plasma (median ICC 0.69) was significantly better than in erythrocytes (median ICC 0.51) (p-value < 0.001). At the class level, reproducibility in plasma was superior for triacylglycerols and cholesteryl esters while ceramides, diacylglycerols, (lyso)phosphatidylethanolamines, and sphingomyelins showed better reproducibility in erythrocytes. Although in plasma overall reproducibility was superior, differences at individual and class levels may favor the use of erythrocytes.
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Rehman H, Ullah I, David M, Ullah A, Jahan S. Neonatal exposure to furan alters the development of reproductive systems in adult male Sprague Dawley rats. Food Chem Toxicol 2019; 130:231-241. [DOI: 10.1016/j.fct.2019.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/02/2019] [Accepted: 05/13/2019] [Indexed: 01/10/2023]
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Edwards CH, Grundy MM, Grassby T, Vasilopoulou D, Frost GS, Butterworth PJ, Berry SE, Sanderson J, Ellis PR. Manipulation of starch bioaccessibility in wheat endosperm to regulate starch digestion, postprandial glycemia, insulinemia, and gut hormone responses: a randomized controlled trial in healthy ileostomy participants. Am J Clin Nutr 2015; 102:791-800. [PMID: 26333512 PMCID: PMC4588739 DOI: 10.3945/ajcn.114.106203] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 07/31/2015] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Cereal crops, particularly wheat, are a major dietary source of starch, and the bioaccessibility of starch has implications for postprandial glycemia. The structure and properties of plant foods have been identified as critical factors in influencing nutrient bioaccessibility; however, the physical and biochemical disassembly of cereal food during digestion has not been widely studied. OBJECTIVES The aims of this study were to compare the effects of 2 porridge meals prepared from wheat endosperm with different degrees of starch bioaccessibility on postprandial metabolism (e.g., glycemia) and to gain insight into the structural and biochemical breakdown of the test meals during gastroileal transit. DESIGN A randomized crossover trial in 9 healthy ileostomy participants was designed to compare the effects of 55 g starch, provided as coarse (2-mm particles) or smooth (<0.2-mm particles) wheat porridge, on postprandial changes in blood glucose, insulin, C-peptide, lipids, and gut hormones and on the resistant starch (RS) content of ileal effluent. Undigested food in the ileal output was examined microscopically to identify cell walls and encapsulated starch. RESULTS Blood glucose, insulin, C-peptide, and glucose-dependent insulinotropic polypeptide concentrations were significantly lower (i.e., 33%, 43%, 40%, and 50% lower 120-min incremental AUC, respectively) after consumption of the coarse porridge than after the smooth porridge (P < 0.01). In vitro, starch digestion was slower in the coarse porridge than in the smooth porridge (33% less starch digested at 90 min, P < 0.05, paired t test). In vivo, the structural integrity of coarse particles (∼2 mm) of wheat endosperm was retained during gastroileal transit. Microscopic examination revealed a progressive loss of starch from the periphery toward the particle core. The structure of the test meal had no effect on the amount or pattern of RS output. CONCLUSION The structural integrity of wheat endosperm is largely retained during gastroileal digestion and has a primary role in influencing the rate of starch amylolysis and, consequently, postprandial metabolism. This trial was registered at isrctn.org as ISRCTN40517475.
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Affiliation(s)
- Cathrina H Edwards
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Myriam Ml Grundy
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Terri Grassby
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Dafni Vasilopoulou
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Gary S Frost
- Nutrition and Dietetic Research Group, Faculty of Medicine, Hammersmith Campus, Imperial College, London, United Kingdom
| | - Peter J Butterworth
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Sarah Ee Berry
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom
| | - Jeremy Sanderson
- Department of Gastroenterology, Guy's and St. Thomas' National Health Service Foundation Trust, London, United Kingdom; and
| | - Peter R Ellis
- Biopolymers Group, Diabetes and Nutritional Sciences Division, King's College London, London, United Kingdom;
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Renaud G, Bouma ME, Foliot A, Infante R. Free fatty-acid uptake by isolated rat hepatocytes. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1985; 93:313-9. [PMID: 2421669 DOI: 10.3109/13813458509079612] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In isolated rat hepatocytes, the rate of palmitic acid binding and uptake is directly related to the concentration of free fatty acid (FFA) in the medium. After their entry into the cell, FFA are immediately incorporated into cellular phospholipids and triglycerides and no accumulation of free fatty acids can be demonstrated inside the cell. The rate of free fatty-acid uptake remains unchanged after incubation in a 2 mM KCN containing medium, indicating that in the range of fatty-acid concentrations used in this study, this phenomenon does not require energy.
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Nicholls DP, Cohen H. Effect of oral and intravenous glucose on alimentary lipaemia in normal man. Ir J Med Sci 1985; 154:348-53. [PMID: 3902710 DOI: 10.1007/bf02937180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
Following a short period of fasting, with free access to water, lipid droplet accumulation (LDA) occurs in many glandular organs as well as in the heart of several species. The present work describes the changes in the hearts of male and female rats of different ages (6, 12, 18 and 24 weeks) deprived of food for 1, 2 and 3 days. LDA was demonstrated by staining with Oil Red O and a special "scoring" system was developed based on sections arbitrarily divided into five regions for each ventricle and two for each atrium. Three standard sections were studied from each heart. This system largely avoided problems arising from the uneven distribution of fats in different parts of the heart. In control animals very little fat was seen in any part of the heart. The pattern of changes was similar in males and females but the degree of LDA was usually much greater in the male. In both sexes LDA increased after 1 day and usually reached a peak by the second day, followed by a sharp decrease, returning to almost normal. However in both sexes the response in the 18-week-old animals was minimal, with no clear peak. The LDA was always maximal in the R ventricle, followed by the L ventricle. The heaviest deposition occurred in the superior parts of the ventricles, close to the atria. LDA was comparatively rare in the atria. Fat appeared to be retained longest in the most heavily loaded regions. Recovery from LDA was rapid, being almost complete 24 hr after returning to a normal diet. Again the most heavily loaded regions retained fat longest. These findings are discussed in related to possible anatomical factors such as the distribution of blood vessels. It is unlikely that such factors offer an adequate explanation abd it is suggested that since the uptake of fats into the heart is probably controlled by lipoprotein lipase the distribution of this enzyme in difference parts of the heart should be investigated. The histochemical changes are also discussed in relation to previous biochemical work. Finally it is pointed out that it is common procedure to fast experimental animals overnight and even such a brief period could bring about considerable histological and metabolic changes.
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Mahmood HA, Marks V. The hypertriglyceridaemia of the cobalt chloride-treated rat: a possible mechanism. Life Sci 1981; 29:627-32. [PMID: 7278505 DOI: 10.1016/0024-3205(81)90441-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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