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Lees HJ, Swann JR, Poucher S, Holmes E, Wilson ID, Nicholson JK. Obesity and Cage Environment Modulate Metabolism in the Zucker Rat: A Multiple Biological Matrix Approach to Characterizing Metabolic Phenomena. J Proteome Res 2019; 18:2160-2174. [PMID: 30939873 DOI: 10.1021/acs.jproteome.9b00040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Obesity and its comorbidities are increasing worldwide imposing a heavy socioeconomic burden. The effects of obesity on the metabolic profiles of tissues (liver, kidney, pancreas), urine, and the systemic circulation were investigated in the Zucker rat model using 1H NMR spectroscopy coupled to multivariate statistical analysis. The metabolic profiles of the obese ( fa/ fa) animals were clearly differentiated from the two phenotypically lean phenotypes, ((+/+) and ( fa/+)) within each biological compartment studied, and across all matrices combined. No significant differences were observed between the metabolic profiles of the genotypically distinct lean strains. Obese Zucker rats were characterized by higher relative concentrations of blood lipid species, cross-compartmental amino acids (particularly BCAAs), urinary and liver metabolites relating to the TCA cycle and glucose metabolism; and lower amounts of urinary gut microbial-host cometabolites, and intermatrix metabolites associated with creatine metabolism. Further to this, the obese Zucker rat metabotype was defined by significant metabolic alterations relating to disruptions in the metabolism of choline across all compartments analyzed. The cage environment was found to have a significant effect on urinary metabolites related to gut-microbial metabolism, with additional cage-microenvironment trends also observed in liver, kidney, and pancreas. This study emphasizes the value in metabotyping multiple biological matrices simultaneously to gain a better understanding of systemic perturbations in metabolism, and also underscores the need for control or evaluation of cage environment when designing and interpreting data from metabonomic studies in animal models.
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Affiliation(s)
- Hannah J Lees
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine , Imperial College London , London , SW7 2AZ , United Kingdom
| | - Jonathan R Swann
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine , Imperial College London , London , SW7 2AZ , United Kingdom
| | - Simon Poucher
- AstraZeneca Pharmaceuticals , Mereside , Alderley Park , Macclesfield , SK10 4TG , United Kingdom
| | - Elaine Holmes
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine , Imperial College London , London , SW7 2AZ , United Kingdom
| | - Ian D Wilson
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine , Imperial College London , London , SW7 2AZ , United Kingdom
| | - Jeremy K Nicholson
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine , Imperial College London , London , SW7 2AZ , United Kingdom
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Elshorbagy AK, Jernerén F, Samocha-Bonet D, Refsum H, Heilbronn LK. Serum S-adenosylmethionine, but not methionine, increases in response to overfeeding in humans. Nutr Diabetes 2016; 6:e192. [PMID: 26807510 PMCID: PMC4742722 DOI: 10.1038/nutd.2015.44] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/19/2015] [Accepted: 11/10/2015] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Plasma concentration of the methyl donor S-adenosylmethionine (SAM) is linearly associated with body mass index (BMI) and fat mass. As SAM is a high-energy compound and a sensor of cellular nutrient status, we hypothesized that SAM would increase with overfeeding. METHODS Forty normal to overweight men and women were overfed by 1250 kcal per day for 28 days. RESULTS Serum SAM increased from 106 to 130 nmol/l (P=0.006). In stratified analysis, only those with weight gain above the median (high-weight gainers; average weight gain 3.9±0.3 kg) had increased SAM (+42%, P=0.001), whereas low-weight gainers (weight gain 1.5±0.2 kg) did not (Pinteraction=0.018). Overfeeding did not alter serum concentrations of the SAM precursor, methionine or the products, S-adenosyl-homocysteine and homocysteine. The SAM/SAH (S-adenosylhomocysteine) ratio was unchanged in the total population, but increased in high-weight gainers (+52%, P=0.006, Pinteraction =0.005). Change in SAM correlated positively with change in weight (r=0.33, P=0.041) and fat mass (r=0.44, P=0.009), but not with change in protein intake or plasma methionine, glucose, insulin or low-density lipoprotein (LDL)-cholesterol. CONCLUSION Overfeeding raised serum SAM in proportion to the fat mass gained. The increase in SAM may help stabilize methionine levels, and denotes a responsiveness of SAM to nutrient state in humans. The role of SAM in human energy metabolism deserves further attention.
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Affiliation(s)
- A K Elshorbagy
- Department of Physiology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - F Jernerén
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - D Samocha-Bonet
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.,Division of Diabetes and Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - H Refsum
- Department of Pharmacology, University of Oxford, Oxford, UK.,Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - L K Heilbronn
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia
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Elshorbagy AK, Nijpels G, Valdivia-Garcia M, Stehouwer CDA, Ocke M, Refsum H, Dekker JM. S-adenosylmethionine is associated with fat mass and truncal adiposity in older adults. J Nutr 2013; 143:1982-8. [PMID: 24068793 DOI: 10.3945/jn.113.179192] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
S-adenosylmethionine (SAM) is synthesized from methionine, which is abundant in animal-derived protein, in an energy-consuming reaction. SAM and S-adenosylhomocysteine (SAH) correlate with body mass index (BMI). Plasma total concentration of the SAM-associated product cysteine (tCys) correlates with fat mass in humans and cysteine promotes adiposity in animals. In a cross-sectional study of 610 participants, we investigated whether SAM and SAH are associated with BMI via lean mass or fat mass and dietary protein sources as determinants of SAM and tCys concentrations. Plasma SAM was not associated with lean mass, but mean adjusted fat mass increased from 24 kg (95% CI: 22.6, 25.1) to 30 kg (95% CI: 28.7, 31.3) across SAM quartiles (P < 0.001) and trunk fat:total fat ratio increased from 0.48 to 0.52 (P < 0.001). Erythrocyte SAM was also positively associated with fat mass and trunk fat:total fat ratio. The association of SAM with fat mass was not weakened by adjustment for serum tCys, lipids, creatinine, or dietary or lifestyle confounders. Concentrations of the SAM precursor, methionine, and the SAM product, SAH, were not independently associated with adiposity. Intake of animal-derived protein was not related to serum methionine but was positively associated with plasma SAM (partial r = 0.11) and serum tCys (partial r = 0.13; P < 0.05 for both after adjustment for age, gender, and total energy intake). In conclusion, plasma SAM, but not methionine, is independently associated with fat mass and truncal adiposity, suggesting increased conversion of methionine to SAM in obese individuals. Prospective studies are needed to investigate the interactions among dietary energy and animal protein content, SAM concentrations, and change in body weight and cardiometabolic risk.
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Protein kinase C isoforms: mediators of reactive lipid metabolites in the development of insulin resistance. FEBS Lett 2010; 585:269-74. [PMID: 21176778 DOI: 10.1016/j.febslet.2010.12.022] [Citation(s) in RCA: 260] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 12/07/2010] [Accepted: 12/14/2010] [Indexed: 11/23/2022]
Abstract
The role of protein kinase C (PKCs) isoforms in the regulation of glucose metabolism by insulin is complex, partly due to the large PKC family consisting of three sub-groups: conventional, novel and atypical. Activation of some conventional and novel PKCs in response to increased levels of diacylglycerol (DAG) have been shown to counteract insulin signalling. However, roles of atypical PKCs (aPKCs) remain poorly understood. aPKCs act as molecular switches by promoting or suppressing signalling pathways, in response to insulin or ceramides respectively. Understanding how DAG- and ceramide-activated PKCs impair insulin signalling would help to develop treatments to fight insulin resistance.
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Wendel AA, Li LO, Li Y, Cline GW, Shulman GI, Coleman RA. Glycerol-3-phosphate acyltransferase 1 deficiency in ob/ob mice diminishes hepatic steatosis but does not protect against insulin resistance or obesity. Diabetes 2010; 59:1321-9. [PMID: 20200319 PMCID: PMC2874692 DOI: 10.2337/db09-1380] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 02/22/2010] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Hepatic steatosis is strongly associated with insulin resistance, but a causal role has not been established. In ob/ob mice, sterol regulatory element binding protein 1 (SREBP1) mediates the induction of steatosis by upregulating target genes, including glycerol-3-phosphate acyltransferase-1 (Gpat1), which catalyzes the first and committed step in the pathway of glycerolipid synthesis. We asked whether ob/ob mice lacking Gpat1 would have reduced hepatic steatosis and improved insulin sensitivity. RESEARCH DESIGN AND METHODS Hepatic lipids, insulin sensitivity, and hepatic insulin signaling were compared in lean (Lep(+/?)), lean-Gpat1(-/-), ob/ob (Lep(ob/ob)), and ob/ob-Gpat1(-/-) mice. RESULTS Compared with ob/ob mice, the lack of Gpat1 in ob/ob mice reduced hepatic triacylglycerol (TAG) and diacylglycerol (DAG) content 59 and 74%, respectively, but increased acyl-CoA levels. Despite the reduction in hepatic lipids, fasting glucose and insulin concentrations did not improve, and insulin tolerance remained impaired. In both ob/ob and ob/ob-Gpat1(-/-) mice, insulin resistance was accompanied by elevated hepatic protein kinase C-epsilon activation and blunted insulin-stimulated Akt activation. CONCLUSIONS These results suggest that decreasing hepatic steatosis alone does not improve insulin resistance, and that factors other than increased hepatic DAG and TAG contribute to hepatic insulin resistance in this genetically obese model. They also show that the SREBP1-mediated induction of hepatic steatosis in ob/ob mice requires Gpat1.
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Affiliation(s)
- Angela A. Wendel
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina
| | - Lei O. Li
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina
| | - Yue Li
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina
| | - Gary W. Cline
- Departments of Internal Medicine and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Gerald I. Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut
| | - Rosalind A. Coleman
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina
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Li YL, Su X, Stahl PD, Gross ML. Quantification of diacylglycerol molecular species in biological samples by electrospray ionization mass spectrometry after one-step derivatization. Anal Chem 2007; 79:1569-74. [PMID: 17297957 PMCID: PMC2573952 DOI: 10.1021/ac0615910] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diacylglycerols (DAGs) are important lipid intermediates in cellular trafficking and signaling. Their concentrations are altered in diabetes, cancer, and other disease states. Quantification of DAGs in biological samples may provide critical information to uncover molecular mechanisms leading to various cellular functional disorders. Recent advances in lipidomics using mass spectrometry have greatly accelerated global lipid analysis and quantification. Quantification of DAGs by electrospray mass spectrometry (ESI/MS), however, is challenged by the absence of a permanent charge on the molecule, its low proton affinity and acidity, and its low abundance under normal biological conditions. We describe here the introduction of a quaternary ammonium cation to DAG molecules, using N-chlorobetainyl chloride, to afford a derivatized DAG that gives 2 orders of magnitude higher signal intensities than their underivatized sodium adducts. A linear calibration curve in which peak intensity ratios are plotted versus molar ratios can be achieved by using ESI/MS with dilauroyl glycerol as the internal standard. Employing this new approach to this analyte, we found a 9-fold increase of total DAGs in the livers of obese db/db mice as compared to their heterozygous lean controls. This proven strategy can be used to detect and quantify DAG molecular species from biological samples using ESI/MS after one-step derivatization.
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Affiliation(s)
- Ying L. Li
- Department of Chemistry, Washington University, St. Louis, MO, 63130
| | - Xiong Su
- Department of Cell Biology and Physiology, Washington University, School of Medicine, St. Louis, MO, 63110
| | - Philip D. Stahl
- Department of Cell Biology and Physiology, Washington University, School of Medicine, St. Louis, MO, 63110
| | - Michael L. Gross
- Department of Chemistry, Washington University, St. Louis, MO, 63130
- Corresponding author: Michael L. Gross, PhD, Department of Chemistry, Washington University, One Brookings Drive, St. Louis, MO, 63130, Tel: 314-935-4814, Fax: 314-935-7484, E-mail:
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Kurosaki E, Nakano R, Momose K, Shimaya A, Suzuki T, Shibasaki M, Shikama H. Hypoglycemic agent YM440 suppresses hepatic glucose output via gluconeogenesis by reducing glucose-6-phosphatase activity in obese Zucker rats. Eur J Pharmacol 2003; 468:151-8. [PMID: 12742522 DOI: 10.1016/s0014-2999(03)01670-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Using a glucose clamp, we had shown that YM440, (Z)-1,4-bis[4-[(3,5-dioxo-1,2,4-oxadiazolidin-2-yl)methyl]phenoxy]but-2-ene, reduced the increased hepatic glucose output in obese Zucker rats. We further examined effects of YM440 on 14C-incorporation from [14C]bicarbonate into blood glucose via gluconeogenesis, and on gluconeogenic enzymatic activities. Fed obese Zucker rats showed a 4-fold increase of 14C-incorporation into blood glucose compared to that in lean rats. Glucose-6-phosphatase and fructose-1,6-bisphosphatase activities in obese rats were increased 1.4-fold and 1.6-fold compared with lean rats. YM440 (300 mg/kg for 2 weeks) decreased 14C-incorporation into blood glucose by 29% in obese rats. Glucose-6-phosphatase but not fructose-1,6-bisphosphatase activity was reduced by YM440 and closely correlated with 14C-incorporation into blood glucose, indicating a key role for glucose-6-phosphatase in hepatic glucose output. These results suggest that the increased gluconeogenesis in obese rats is mainly due to the increased activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase and that YM440 suppresses hepatic glucose output by reducing glucose-6-phosphatase activity.
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Affiliation(s)
- Eiji Kurosaki
- Pharmacology Laboratories, Institute for Drug Discovery Research, Yamanouchi Pharmaceutical Co, Ltd, Ibaraki, Tsukuba, Japan
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Krasilnikova OA, Kavok NS, Babenko NA. Drug-induced and postnatal hypothyroidism impairs the accumulation of diacylglycerol in liver and liver cell plasma membranes. BMC PHYSIOLOGY 2002; 2:12. [PMID: 12182762 PMCID: PMC126221 DOI: 10.1186/1472-6793-2-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2002] [Accepted: 08/16/2002] [Indexed: 11/17/2022]
Abstract
BACKGROUND Thyroid hormones are well known modulators of signal transduction. The effect of hyper- and hypo-thyroidism on diacylglycerol/protein kinase C (DAG/PKC) signaling in cardiomiocytes has been determined. Triiodothyronine (T3) has been shown to prevent the alpha1-adrenoreceptor-mediated activation of PKC but does not alter the stimulation of enzyme and hepatic metabolism by phorbol ethers. It has been suggested that the elevation of endogenous DAG in senescent or hypothyroid cells changes the PKC-dependent response of cells to phorbol esters and hormones. In the present study, was examined the formation of DAG and activation of PKC in liver cells from rats of different thyroid status. RESULTS The results obtained provide the first demonstration of DAG accumulation in liver and cell plasma membranes at age- and drug-dependent thyroid gland malfunction. The experiments were performed in either the [14C]CH3COOH-labeled rat liver, liver slices or hepatocytes labeled by [14C] oleic acid and [3H]arachidonic acid or [14C]palmitic acid as well as in the isolated liver cell plasma membranes of 90- and 720-day-old rats of different thyroid status. The decrease of T4 and T3 levels in blood serum of 720-day-old rats and mercazolil-treated animals was associated with increases of both the DAG mass in liver and liver cell plasma membranes and newly synthesized [14C]DAG level in liver and isolated hepatocytes. Hypothyroidism decreased PKC activity in both membrane and cytosol as well as phospholipid and triacylglycerol synthesis in liver. These hypothyroidism effects were restored in liver by injection of T4. T4 administration to the intact animals of different ages decreased the DAG level in liver and isolated plasma membranes and the content of newly synthesized DAG in liver. The reduction of DAG level in liver was not associated with increasing free fatty acid level. DAG labeling ratio 14C/3H in liver slices of rats of different thyroid state sharply differed from PL. DAG was relatively enriched in [14C]oleic acid whereas PL were enriched in [3H]arachidonic acid. CONCLUSIONS The above data have indicated that thyroid hormones are important physiological modulators of DAG level in rat liver and cell plasma membranes. Age- and drug-induced malfunction of thyroid gland resulted in a prominent decrease of glycerolipid synthesis which may promote DAG accumulation in liver.
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Affiliation(s)
- Oksana A Krasilnikova
- Kharkov National University, Institute of Biology, 4, Svobody pl., Kharkov, 61077, Ukraine
| | - Nataliya S Kavok
- Kharkov National University, Institute of Biology, 4, Svobody pl., Kharkov, 61077, Ukraine
| | - Nataliya A Babenko
- Kharkov National University, Institute of Biology, 4, Svobody pl., Kharkov, 61077, Ukraine
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Morabito D, Montessuit C, Rosenblatt-Velin N, Lerch R, Vallotton MB, Lang U. Impaired glucose metabolism in the heart of obese Zucker rats after treatment with phorbol ester. Int J Obes (Lond) 2002; 26:327-34. [PMID: 11896487 DOI: 10.1038/sj.ijo.0801881] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2001] [Revised: 08/07/2001] [Accepted: 10/01/2001] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To investigate the influence of obesity on the regulation of myocardial glucose metabolism following protein kinase C (PKC) activation in obese (fa/fa) and lean (Fa/?) Zucker rats. DESIGN Isolated hearts obtained from 17-week-old lean and obese Zucker rats were perfused with 200 nM phorbol 12-myristate 13-acetate (PMA) for different time periods prior to the evaluation of PKC and GLUT-4 translocation. For metabolic studies isolated hearts from 48 h starved Zucker rats were perfused with an erythrocytes-enriched buffer containing increased concentrations (10-100 nM) of PMA. MEASUREMENTS Immunodetectable PKC isozymes and GLUT-4 were determined by Western blots. Glucose oxidation and glycolysis were evaluated by measuring the myocardial release of 14CO2 and 3H2O from [U-14C]glucose and [5-3H]glucose, respectively. RESULTS PMA (200 nM) induced maximal translocation of ventricular PKCalpha from the cytosol to the membranes within 10 min. This translocation was 2-fold lower in the heart from obese rats when compared to lean rats. PMA also induced a significant translocation of ventricular GLUT-4 from the microsomal to the sarcolemmal fraction within 60 min in lean but not in obese rats. Rates of basal cardiac glucose oxidation and glycolysis in obese rats were approximately 2-fold lower than those of lean rats. Perfusion with increasing concentrations of PMA (10-100 nM) led to a significant decrease of cardiac glucose oxidation in lean but not in obese rats. CONCLUSION Our results show that in the heart of the genetically obese Zucker rat, the impairment in PKCalpha activation is in line with a diminished activation of GLUT-4 as well as with the lack of PMA effect on glucose oxidation.
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Affiliation(s)
- D Morabito
- Division of Endocrinology and Diabetology, Department of Internal Medicine, University Hospital of Geneva, Geneva, Switzerland
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Morabito D, Vallotton MB, Lang U. Obesity is associated with impaired ventricular protein kinase C-MAP kinase signaling and altered ANP mRNA expression in the heart of adult Zucker rats. J Investig Med 2001; 49:310-8. [PMID: 11478406 DOI: 10.2310/6650.2001.33895] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND In the obesity model of the Zucker rat, myocardial protein kinase C (PKC) activation by phorbol ester is impaired. The influence of obesity on myocardial cell signaling was investigated by studying the activation of PKC isozymes and MAP kinases (MAPK) p38 and p42/44 as well as the induction of ANP mRNA. METHODS Isolated hearts obtained from 17-week-old lean and obese Zucker rats were perfused with 200 nM phorbol 12-myristate 13-acetate (PMA) at different time periods. Immunodetectable PKC isozymes, phosphorylated-MAPK, and ANP mRNA were determined by Western and Northern blots, respectively. RESULTS PMA promoted a marked transient translocation of ventricular PKCalpha from the cytosol to the membranes within 10 minutes in lean rats, whereas it had a much weaker effect in obese rats. Moreover, PMA induced a significant activation of PKCdelta in lean but not in obese rat hearts. After PKC activation, increases in phosphorylation levels of myocardial p38 and p42 MAPK were approximately 3-fold higher in lean rats than in obese animals. Concerning the induction of ANP, PMA transiently tripled ANP mRNA within 60 minutes in lean but not in obese rats. CONCLUSIONS In the genetically obese Zucker rat, the myocardial signal transduction cascade PKC-MAPK-ANP mRNA seems to be markedly impaired. It can be speculated that this abnormal cardiac cell signaling in obese rats reflects an early phase in the cardiac pathogenesis accompanying obesity.
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Affiliation(s)
- D Morabito
- Division of Endocrinology and Diabetology, University Hospital, Geneva, Switzerland
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Abstract
Distinct, structurally different forms of sn-1,2-diacylglycerol are found in cells, these are polyunsaturated, mono- or di-unsaturated and saturated. The pathways that generate or metabolise sn-1, 2-diacylglycerol are reviewed. The evidence that it is the polyunsaturated forms of sn-1,2-diacylglycerol, but the more saturated forms of phosphatidate which function as intracellular signals is considered.
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Affiliation(s)
- M J Wakelam
- Institute for Cancer Studies, Birmingham University, Queen Elizabeth Hospital, Clinical Research Block, Birmingham B15 2TA, UK.
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