ABSTRACT
Pyruvate dehydrogenase kinases (PDK1-4) inhibit the TCA cycle by phosphorylating pyruvate dehydrogenase complex (PDC). Here, we show that PDK family is dispensable for murine embryonic development and that BCKDK serves as a compensatory mechanism by inactivating PDC. First, we knocked out all four Pdk genes one by one. Surprisingly, Pdk total KO embryos developed and were born in expected ratios but died by postnatal day 4 because of hypoglycemia or ketoacidosis. Moreover, PDC was phosphorylated in these embryos, suggesting that another kinase compensates for PDK family. Bioinformatic analysis implicated branched-chain ketoacid dehydrogenase kinase (Bckdk), a key regulator of branched-chain amino acids (BCAAs) catabolism. Indeed, knockout of Bckdk and Pdk family led to the loss of PDC phosphorylation, an increase in PDC activity and pyruvate entry into the TCA cycle, and embryonic lethality. These findings reveal a regulatory crosstalk hardwiring BCAA and glucose catabolic pathways, which feed the TCA cycle.
Subject(s)
Citric Acid Cycle , Embryonic Development , Protein Kinases/metabolism , Pyruvate Dehydrogenase Acetyl-Transferring Kinase/metabolism , Pyruvate Dehydrogenase Complex/metabolism , Animals , Animals, Newborn , Embryo Loss/enzymology , Embryo Loss/pathology , Gene Deletion , Hypoglycemia/complications , Hypoglycemia/enzymology , Hypoglycemia/pathology , Ketosis/complications , Ketosis/enzymology , Ketosis/pathology , Mice, Knockout , Models, Biological , Phosphorylation , Pyruvic Acid/metabolismABSTRACT
Fatty acids (FA) provide an energy source to the liver during negative energy balance; however, when FA influx is excessive, FA can be stored as liver lipids or incompletely oxidized to ß-hydroxybutyrate (BHB). The objectives of this study were to quantify plasma and liver FA profiles and hepatic gene expression in cows diagnosed with hyperketonemia (HYK; BHB ≥ 1.2 mM) or not (nonHYK; BHB < 1.2 mM) to determine a relationship between FA profile and expression of hepatic genes related to oxidation and gluconeogenesis. Production parameters, blood samples (-28, -3, 1, 3, 5, 7, 9, 11, and 14 d relative to parturition; n = 28 cows), and liver biopsies (1, 14, and 28 d postpartum; n = 22 cows) were collected from Holstein cows. Cows were retrospectively grouped as HYK or nonHYK based on BHB concentrations in postpartum blood samples. Average first positive test (BHB ≥ 1.2 mM) was 9 ± 5 d (± SD). Cows diagnosed with HYK had greater C18:1 and lower C18:2 plasma proportions. Liver FA proportions of C16:0 and C18:1 were related to proportions in plasma, but C18:0 and C18:2 were not. Some interactions between plasma FA and HYK on liver FA proportion suggests that there may be preferential use depending upon metabolic state. Cows diagnosed with HYK had decreased pyruvate carboxylase (PC) expression, but no difference at 1 d postpartum in either cytosolic or mitochondrial isoforms of phosphoenolpyruvate carboxykinase (PCK). The increased PC to PCK ratios in nonHYK cows suggests the potential for greater hepatic oxidative capacity, coinciding with decreased circulating BHB. Interestingly, FA, known regulators of PC expression, were not correlated with PC expression at 1 d postpartum. Taken together, these data demonstrate that HYK cows experience a decrease in the ratio of hepatic PC to PCK at 1 day postpartum prior to HYK diagnosis which, on average, manifested a week later. The differential regulation of PC involved in HYK diagnosis may not be completely due to shifts in FA profiles and warrants further investigation.
Subject(s)
Cattle Diseases/enzymology , Ketosis/veterinary , Pyruvate Carboxylase/metabolism , Age of Onset , Animals , Cattle , Cattle Diseases/metabolism , Fatty Acids/blood , Fatty Acids/metabolism , Female , Ketosis/enzymology , Ketosis/metabolism , Liver/metabolism , Retrospective StudiesABSTRACT
The objective of this study was to evaluate the association between ketonemia and serum paraoxonase-1 (PON1), malondialdehyde (MDA), and other blood components in tail and mammary veins of dairy cows. Forty-two Holstein dairy cows with decreased feed intake were divided into HIGH (≥ 1.2 mM; n = 31) and LOW (< 1.2 mM; n = 11) groups based on the ß-hydroxybutyrate concentration in plasma collected from the tail vein. The HIGH group had a significantly greater plasma non-esterified fatty acid (NEFA) concentration, but significantly lower serum PON1 activity and phospholipid concentration, and a tendency to have a lower cholesterol ester concentration than the LOW group. Serum PON1 activity was not correlated with the MDA concentration but was positively correlated with serum concentrations of cholesterol esters and phospholipids, and negatively correlated with the plasma NEFA concentration. These results suggest that serum PON1 activity is reduced by hyperketonemia and the relevance of PON1 to MDA seems to not be direct, though it is involved.
L'objectif de la présente étude était d'évaluer l'association entre l'acétonémie et la paraoxonase-1 (PON1), le malondialdéhyde (MDA), et d'autres composés du sang dans les veines caudale et mammaire de vaches laitières. Quarante-deux vaches laitières de race Holstein présentant une diminution de l'ingestion d'aliments furent divisées en groupes ÉLEVÉ (≥ 1,2 mM; n = 31) et BAS (< 1,2 mM; n = 11) basés sur la concentration de ß-hydroxybutyrate de plasma prélevé de la veine caudale. Le groupe ÉLEVÉ avait une concentration plasmatique significativement plus grande d'acides gras non-estérifiés (NEFA), mais le sérum présentait une activité PON1 et une concentration de phospholipides significativement réduite, et une tendance à avoir une concentration d'esters de cholestérol plus faible que le groupe BAS. L'activité de PON1 sérique n'était pas corrélée avec la concentration de MDA mais était corrélée positivement avec les concentrations sériques d'esters de cholestérol et de phospholipides, et corrélée négativement avec la concentration plasmatique de NEFA. Ces résultats suggèrent que l'activité de PON1 sérique est réduite par l'hypercétonémie et la pertinence de PON1 envers MDA ne semble pas être directe, bien qu'elle semble impliquée.(Traduit par Docteur Serge Messier).
Subject(s)
Aryldialkylphosphatase/blood , Cattle Diseases/enzymology , Ketosis/veterinary , Malondialdehyde/blood , 3-Hydroxybutyric Acid/blood , Animals , Blood Chemical Analysis/veterinary , Cattle , Cattle Diseases/blood , Cholesterol Esters/blood , Colorimetry/veterinary , Fatty Acids, Nonesterified/blood , Female , Ketosis/blood , Ketosis/enzymology , Mammary Glands, Animal/blood supply , Phospholipids/blood , Tail/blood supplyABSTRACT
Dairy cows with ketosis display severe oxidative stress as well as high blood concentrations of non-esterified fatty acids (NEFA) and ß-hydroxybutyrate (BHB). Cytochrome P4502E1 (CYP2E1) plays an important role in the induction of oxidative stress. The aim of this study was to investigate CYP2E1 expression and activity in the liver of clinically ketotic cows (in vivo) and the effects of NEFA and BHB on CYP2E1 expression and activity in hepatocytes (in vitro). Dairy cows with clinical ketosis exhibited a low blood concentration of glucose but high concentrations of NEFA and BHB. Hepatic mRNA, protein expression, and activity of CYP2E1 were significantly higher in cows with clinical ketosis than in control cows. In vitro, both NEFA and BHB treatment markedly up-regulated the mRNA and protein expressions as well as activity of CYP2E1 in cow hepatocytes. Taken together, these results indicate that high levels of NEFA and BHB significantly up-regulate the expression and activity of hepatic CYP2E1, and may be influential in the induction of oxidative stress in cows with clinical ketosis.
Subject(s)
3-Hydroxybutyric Acid/pharmacology , Cattle Diseases/enzymology , Cytochrome P-450 CYP2E1/drug effects , Fatty Acids, Nonesterified/pharmacology , Ketosis/enzymology , Liver/enzymology , 3-Hydroxybutyric Acid/blood , Animals , Cattle , Cattle Diseases/blood , China , Cytochrome P-450 CYP2E1/genetics , Cytochrome P-450 CYP2E1/metabolism , Dairying , Fatty Acids, Nonesterified/blood , Female , Gene Expression/drug effects , Hepatocytes/drug effects , Hepatocytes/enzymology , Ketosis/blood , Oxidative Stress/drug effects , RNA, Messenger/analysis , Up-Regulation/drug effectsABSTRACT
IQ motif-containing GTPase-activating protein 1 (IQGAP1) is a ubiquitously expressed scaffolding protein that integrates multiple cellular processes, including motility, adhesion, and proliferation, but its role in metabolism is unknown. Here, we show that IQGAP1 is induced upon fasting and regulates ß-oxidation of fatty acids and synthesis of ketone bodies in the liver. IQGAP1-null (Iqgap1-/-) mice exhibit reduced hepatic PPARα transcriptional activity, as evidenced during fasting, after ketogenic diet, and upon pharmacological activation. Conversely, we found that the activity of fed-state sensor mTORC1 is enhanced in Iqgap1-/- livers, but acute inhibition of mTOR in Iqgap1-/- mice was unable to rescue the defect in ketone body synthesis. However, reexpressing IQGAP1 in the livers of Iqgap1-/- mice was sufficient to promote ketone body synthesis, increase PPARα signaling, and suppress mTORC1 activity. Taken together, we uncover what we believe to be a previously unidentified role for IQGAP1 in regulating PPARα activity and ketogenesis.
Subject(s)
Fasting/metabolism , Ketosis/enzymology , Liver/metabolism , ras GTPase-Activating Proteins/metabolism , Animals , Cell Movement/physiology , Cell Proliferation/physiology , Fatty Acids/metabolism , Ketosis/metabolism , Liver/pathology , Male , Mice , Oxidation-Reduction , Signal Transduction , TOR Serine-Threonine KinasesABSTRACT
CONTEXT: Ketonuria, which reflects a preferential combustion of lipids relative to carbohydrates, is often observed in lean rather than obese people. Clinical studies have shown that individuals with diabetes and/or obesity predispose to have low serum amylase (LSA). OBJECTIVE: To investigate the association between ketonuria and LSA. METHODS: We examined ketonuria assessed by dipstick urinalysis and clinical parameters including serum amylase in 3638 Japanese people aged 25-79 years who underwent a health-screening checkup. RESULTS: There was an inverse relationship between body mass index (BMI) and serum amylase. The lowest serum amylase was observed in obese subjects (BMI ≥ 25.0 kg/m2) with positive ketonuria. Logistic regression analysis showed that ketonuria was significantly associated with LSA (<50 IU/L), which was not altered by the adjustments for relevant confounders including age, sex, BMI, and HbA1c. CONCLUSIONS: Current results suggest a relative unavailability of carbohydrates for energy production in individuals with LSA.
Subject(s)
Amylases/blood , Ketosis/blood , Ketosis/enzymology , Body Weight , Female , Glucose/metabolism , Humans , Male , Middle AgedABSTRACT
Many individuals with abnormalities of mitochondrial respiratory chain complex III remain genetically undefined. Here, we report mutations (c.288G>T [p.Trp96Cys] and c.643C>T [p.Leu215Phe]) in CYC1, encoding the cytochrome c1 subunit of complex III, in two unrelated children presenting with recurrent episodes of ketoacidosis and insulin-responsive hyperglycemia. Cytochrome c1, the heme-containing component of complex III, mediates the transfer of electrons from the Rieske iron-sulfur protein to cytochrome c. Cytochrome c1 is present at reduced levels in the skeletal muscle and skin fibroblasts of affected individuals. Moreover, studies on yeast mutants and affected individuals' fibroblasts have shown that exogenous expression of wild-type CYC1 rescues complex III activity, demonstrating the deleterious effect of each mutation on cytochrome c1 stability and complex III activity.
Subject(s)
Cytochromes c1/genetics , Cytochromes c/genetics , Hyperglycemia/genetics , Ketosis/genetics , Mutation , Protein Subunits/genetics , Saccharomyces cerevisiae Proteins/genetics , Amino Acid Sequence , Child, Preschool , Consanguinity , Cytochromes c/metabolism , Cytochromes c1/metabolism , Electron Transport , Female , Fibroblasts/enzymology , Fibroblasts/pathology , Genetic Complementation Test , Humans , Hyperglycemia/drug therapy , Hyperglycemia/enzymology , Hyperglycemia/physiopathology , Insulin/pharmacology , Iron-Sulfur Proteins/genetics , Iron-Sulfur Proteins/metabolism , Ketosis/drug therapy , Ketosis/enzymology , Ketosis/physiopathology , Male , Mitochondria/enzymology , Mitochondria/genetics , Models, Molecular , Molecular Sequence Data , Protein Subunits/metabolism , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/metabolism , Skin/enzymology , Skin/pathologyABSTRACT
Type 1 diabetic patients have hyperketonemia, elevated levels of pro-inflammatory and oxidative stress markers, and a higher incidence of vascular disease. This study examines the hypothesis that hyperketonemia increases reactive oxygen species (ROS) and is in part responsible for increased expression of adhesion molecules in monocytes. THP-1 monocytes were treated with acetoacetate (AA) or ß-hydroxybutyrate (BHB) (0-10 mmol/L) for 24 h. Results show that AA, but not BHB, increases ROS production in monocytes. Pretreatment of monocytes with N-acetylcysteine (NAC) inhibited AA-induced ROS production. AA treatment induced upregulation of LFA-1 and pretreatment of monocytes with NAC or an inhibitor to p38 MAPK inhibited this upregulation in monocytes. This suggests that physiological concentrations of AA can contribute to increased ROS and activation of p38 MAPK, which may be responsible for AA-induced upregulation of LFA-1 in monocytes. Thus, hyperketonemia contributes to the risk for cardiovascular disease in type 1 diabetes.
Subject(s)
Ketosis/metabolism , Lymphocyte Function-Associated Antigen-1/metabolism , Monocytes/metabolism , Reactive Oxygen Species/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , 3-Hydroxybutyric Acid/pharmacology , Acetoacetates/pharmacology , Acetylcysteine/pharmacology , Cardiovascular Diseases/enzymology , Cardiovascular Diseases/genetics , Cardiovascular Diseases/metabolism , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , Cells, Cultured , Humans , Ketosis/enzymology , Ketosis/genetics , Lymphocyte Function-Associated Antigen-1/genetics , MAP Kinase Signaling System , Monocytes/enzymology , Oxidative Stress/drug effects , Oxidative Stress/genetics , Up-Regulation , p38 Mitogen-Activated Protein Kinases/geneticsABSTRACT
Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid ß-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), ß-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid ß-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.
Subject(s)
Cattle Diseases/enzymology , Fatty Acids/metabolism , Ketosis/veterinary , Liver/enzymology , Puerperal Disorders/veterinary , 3-Hydroxybutyric Acid/blood , Acetyl-CoA Carboxylase/analysis , Acetyl-CoA Carboxylase/genetics , Acyl-CoA Dehydrogenases/analysis , Acyl-CoA Dehydrogenases/genetics , Animals , Blood Glucose/analysis , Carnitine O-Palmitoyltransferase/analysis , Carnitine O-Palmitoyltransferase/genetics , Cattle , Coenzyme A Ligases/analysis , Coenzyme A Ligases/genetics , Fatty Acids, Nonesterified/blood , Female , Hydroxymethylglutaryl-CoA Synthase/analysis , Hydroxymethylglutaryl-CoA Synthase/genetics , Ketosis/enzymology , Oxidation-Reduction , Puerperal Disorders/enzymology , RNA, Messenger/analysisABSTRACT
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency causes episodic ketoacidotic crises and no apparent symptoms between them. Here, we report a Japanese case of neonatal-onset SCOT deficiency. The male patient presented a severe ketoacidotic crisis, with blood pH of 7.072 and bicarbonate of 5.8 mmol/L at the age of 2 days and was successfully treated with intravenous infusion of glucose and sodium bicarbonate. He was diagnosed as SCOT deficient by enzymatic assay and mutation analysis. At the age of 7 months, he developed a second ketoacidotic crisis, with blood pH of 7.059, bicarbonate of 5.4 mmol/L, and total ketone bodies of 29.1 mmol/L. He experienced two milder ketoacidotic crises at the ages of 1 year and 7 months and 3 years and 7 months. His urinary ketone bodies usually range from negative to 1+ but sometimes show 3+ (ketostix) without any symptoms. Hence, this patient does not show permanent ketonuria, which is characteristic of typical SCOT-deficient patients. He is a compound heterozygote of c.1304C > A (T435N) and c.658-666dupAACGTGATT p.N220_I222dup. mutations in the OXCT1 gene. The T435N mutation was previously reported as one which retained significant residual activity. The latter novel mutation was revealed to retain no residual activity by transient expression analysis. Both T435N and N220_I222 lie close to the SCOT dimerization interface and are not directly connected to the active site in the tertiary structure of a human SCOT dimer. In transient expression analysis, no apparent interallelic complementation or dominant negative effects were observed. Significant residual activity from the T435N mutant allele may prevent the patient from developing permanent ketonuria.
Subject(s)
Acidosis/genetics , Coenzyme A-Transferases/deficiency , Ketosis/genetics , Mutation , Acidosis/blood , Acidosis/diagnosis , Acidosis/drug therapy , Acidosis/enzymology , Cells, Cultured , Child, Preschool , Coenzyme A-Transferases/blood , Coenzyme A-Transferases/chemistry , Coenzyme A-Transferases/genetics , DNA Mutational Analysis , Genetic Predisposition to Disease , Glucose/administration & dosage , Humans , Infant , Infant, Newborn , Infusions, Intravenous , Japan , Ketosis/blood , Ketosis/diagnosis , Ketosis/drug therapy , Ketosis/enzymology , Male , Models, Molecular , Phenotype , Protein Conformation , Protein Multimerization , Recurrence , Sodium Bicarbonate/administration & dosage , Time Factors , Transfection , Treatment OutcomeABSTRACT
Lecithin cholesterol acyltransferase (LCAT) activity was measured in 48 Egyptian water buffaloes four weeks pre-parturient. The activity was significantly low in 37 buffaloes (77.1%). Four weeks post-partum, clinical examination revealed that 23 buffaloes had the clinical signs of ketosis (K) while 14 had the clinical signs of parturient-haemoglobinuria (PHU). Serum samples were collected from 5 buffaloes of each group (K and PHU) besides 5 clinically healthy buffaloes with normal LCAT (control). Glucose level was significantly reduced in K and PHU groups while the phosphorous (P) level was significantly reduced in PHU group compared to control. There were significant reductions in the total cholesterol, free cholesterol, triglycerides, total protein and albumin in K and PHU groups; whereas, significant increases in AST, GGT, non-esterified fatty acids (NEFA) and beta-hydroxybutyric acid (BHBA) in K and PHU groups were detected. Therefore, LCAT could be a predictor for metabolic disorders in Egyptian water buffaloes.
Subject(s)
Buffaloes/blood , Hemoglobinuria/veterinary , Ketosis/enzymology , Ketosis/veterinary , Phosphatidylcholine-Sterol O-Acyltransferase/blood , Pregnancy Complications/veterinary , 3-Hydroxybutyric Acid/blood , Animals , Blood Glucose/analysis , Blood Proteins/analysis , Cholesterol/blood , Fatty Acids, Nonesterified/blood , Fatty Liver/blood , Fatty Liver/enzymology , Fatty Liver/veterinary , Female , Hemoglobinuria/enzymology , Phosphorus/blood , Predictive Value of Tests , Pregnancy , Pregnancy Complications/enzymology , Serum Albumin/analysis , Triglycerides/bloodABSTRACT
Diabetic patients frequently encounter ketosis that is characterized by the breakdown of lipids with the consequent accumulation of ketone bodies. Several studies have demonstrated that reactive species are likely to induce tissue damage in diabetes, but the role of the ketone bodies in the process has not been fully investigated. In this study, electron paramagnetic resonance (EPR) spectroscopy combined with novel spin-trapping and immunological techniques has been used to investigate in vivo free radical formation in a murine model of acetone-induced ketosis. A six-line EPR spectrum consistent with the alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone radical adduct of a carbon-centered lipid-derived radical was detected in the liver extracts. To investigate the possible enzymatic source of these radicals, inducible nitric oxide synthase (iNOS) and NADPH oxidase knockout mice were used. Free radical production was unchanged in the NADPH oxidase knockout but much decreased in the iNOS knockout mice, suggesting a role for iNOS in free radical production. Longer-term exposure to acetone revealed iNOS overexpression in the liver together with protein radical formation, which was detected by confocal microscopy and a novel immunospin-trapping method. Immunohistochemical analysis revealed enhanced lipid peroxidation and protein oxidation as a consequence of persistent free radical generation after 21 days of acetone treatment in control and NADPH oxidase knockout but not in iNOS knockout mice. Taken together, our data demonstrate that acetone administration, a model of ketosis, can lead to protein oxidation and lipid peroxidation through a free radical-dependent mechanism driven mainly by iNOS overexpression.
Subject(s)
Free Radicals/metabolism , Ketosis/metabolism , Nitric Oxide Synthase Type II/metabolism , Proteins/metabolism , Acetone/pharmacology , Animals , Electron Spin Resonance Spectroscopy , Immunohistochemistry , Ketosis/chemically induced , Ketosis/enzymology , Lipid Metabolism/drug effects , Liver/drug effects , Liver/metabolism , Liver/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Confocal , NADPH Oxidases/deficiency , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type II/genetics , Oxidation-Reduction , Protein Carbonylation , Pyridines/chemistry , RNA/chemistry , RNA/genetics , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Thirty-five multiparous Holstein cows were used to determine the role of mitochondrial carnitine palmitoyltransferase I (CPT I) in liver on peripartal adaptations of fatty acid metabolism. From dry-off to parturition, cows were fed a diet at either ad libitum (n = 17) or restricted intake (RI, 80% of calculated requirements for net energy; n = 18). After parturition, all cows were fed a lactation diet. At 4 d in milk (DIM), cows underwent a physical examination and were classified as healthy (n = 15) or having at least one periparturient disorder (PD; n = 17). Cows in the healthy group were assigned to either a control (n = 6) group or a ketosis induction (KI; n = 9) group. Cows with periparturient disorders were assigned to a third (PDC; n = 17) group. Cows in control and PDC groups were fed for ad libitum intake. Cows in KI were fed at 50% of their respective intake at d 4 postpartum starting from 5 DIM and continuing to signs of clinical ketosis or until 14 DIM; cows then were returned to ad libitum intake. Liver was biopsied at -30 d, 1 d, at signs of clinical ketosis or 14 d, and 28 d relative to parturition. Mitochondria were isolated by differential centrifugation. Activity of CPT I was 5.4 and 7.6 nmol of palmitoylcarnitine formed per min/mg of protein for ad libitum and RI, respectively, at -30 DIM. Sensitivity of CPT I to its inhibitor, malonyl CoA, did not differ between ad libitum and RI cows. Differences in CPT I activity between ad libitum and RI were no longer significant at 1 DIM. Postpartum CPT I activity and malonyl CoA sensitivity at 1 DIM, onset of clinical ketosis or 14 DIM, and 28 DIM were not affected by prepartum intake (ad libitum vs. RI), postpartum health status (healthy vs. PD), or ketosis induction status (control vs. KI vs. PDC). Activity of CPT I was positively correlated with liver total lipid, liver triglyceride, liver triglyceride to glycogen ratio, and serum nonesterified fatty acids. Activity of CPT I and dry matter intake were not correlated. Prepartum intake affected prepartum CPT I activity but not malonyl CoA sensitivity. Neither induction of primary ketosis nor periparturient disorders greatly affected CPT I activity or sensitivity, which indicates that alterations of CPT I may not be a major factor in the etiology of primary ketosis or other periparturient disorders.
Subject(s)
Carnitine O-Palmitoyltransferase/metabolism , Cattle Diseases/enzymology , Diet , Ketosis/veterinary , Mitochondria, Liver/enzymology , Parturition , 3-Hydroxybutyric Acid/blood , Animals , Carnitine O-Palmitoyltransferase/antagonists & inhibitors , Cattle , Energy Intake , Enzyme Inhibitors/pharmacology , Fatty Acids, Nonesterified/blood , Female , Glycogen/analysis , Ketone Bodies/blood , Ketosis/enzymology , Kinetics , Lipids/analysis , Liver/chemistry , Malonyl Coenzyme A/pharmacology , Pregnancy , Puerperal Disorders/enzymology , Puerperal Disorders/veterinary , Triglycerides/analysisSubject(s)
3-Hydroxybutyric Acid/urine , Acetoacetates/urine , Acidosis, Lactic/enzymology , Carbon-Nitrogen Ligases/deficiency , Ketosis/enzymology , Lactic Acid/urine , Acidosis, Lactic/urine , Carboxy-Lyases/metabolism , Child , Humans , Ketosis/urine , Male , Methylmalonyl-CoA Decarboxylase , Pyruvate Carboxylase/metabolismABSTRACT
Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for production of cholesteryl esters in plasma. The LCAT activity is reduced in cows with fatty liver developed during the nonlactating stage and those with the fatty liver-related postparturient diseases such as ketosis. The purpose of the present study was to examine whether reduced LCAT activity during the nonlactating stage could be detected before the occurrence of postparturient diseases. Sera from 24 cows were collected at approximately 10-day intervals from -48 to +14 days from parturition. Of the 24 cows, 14 were apparently healthy, whereas 7 had ketosis and 3 had milk fever at around parturition. Of the 14 healthy cows, 7 had unaltered LCAT activity during the observation period, whereas 7 showed reduced activity from -20 to +14 days. Ketosis and milk fever occurred at from -3 to +10 days, but reductions of LCAT activity in diseased cows had already been observed from days -20 to 0. These results suggest that LCAT activity is virtually unaffected during the peripartum period at least in some healthy cows and also that the reduction in LCAT activity can be detected before the occurrence of ketosis and milk fever.
Subject(s)
Cattle Diseases/enzymology , Ketosis/veterinary , Parturient Paresis/enzymology , Phosphatidylcholine-Sterol O-Acyltransferase/blood , Animals , Apolipoprotein B-100 , Apolipoproteins B/blood , Aspartate Aminotransferases/blood , Blotting, Western/veterinary , Cattle , Cattle Diseases/pathology , Cholesterol/blood , Cholesterol Esters/blood , Fatty Acids/blood , Fatty Liver/enzymology , Fatty Liver/pathology , Fatty Liver/veterinary , Female , Ketosis/enzymology , Phospholipids/blood , Postpartum Period , Pregnancy , Triglycerides/bloodSubject(s)
Autoantibodies/analysis , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 2/immunology , Glutamate Decarboxylase/immunology , Ketosis/complications , Adult , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/enzymology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/enzymology , Humans , Insulin/immunology , Islets of Langerhans/immunology , Ketosis/enzymology , Male , Middle AgedABSTRACT
Lecithin:cholesterol acyltransferase (LCAT) activity was evaluated in sera from cows with ketosis and in some with left displacement of the abomasum (LDA) that occurred during early lactation. The enzyme activities of 652 +/- 214 U (mean +/- SD) in cows with ketosis (n = 6) and 683 +/- 110 U in those with LDA (n = 5) were significantly (p < 0.01) decreased compared to those in healthy normal cows (994 +/- 65 U, n = 8). Serum concentrations of free cholesterol, cholesteryl esters (CE) and phospholipids were similarly decreased in the two diseases. Cows whose LCAT activity and CE concentration were lower than the normal values were detected while in the non-lactating stage, and some of these cows had ketosis after parturition. It is suggested that evaluation of the LCAT activity and of the CE concentration during the non-lactating stage would be useful in detecting cows that are susceptible to postparturient disorders such as ketosis.
Subject(s)
Abomasum/physiopathology , Cattle Diseases/physiopathology , Ketosis/veterinary , Phosphatidylcholine-Sterol O-Acyltransferase/physiology , Animals , Apolipoprotein B-100 , Apolipoproteins B/blood , Aspartate Aminotransferases/blood , Cattle , Cattle Diseases/enzymology , Cholesterol/blood , Cholesterol Esters/blood , Fatty Acids, Nonesterified/blood , Fatty Liver/physiopathology , Fatty Liver/veterinary , Female , Ketosis/enzymology , Ketosis/physiopathology , Lactation , Phosphatidylcholine-Sterol O-Acyltransferase/blood , Phospholipids/blood , Triglycerides/bloodABSTRACT
UNLABELLED: We describe the clinical symptoms and biochemical findings of a patient with succinyl-CoA:acetoacetate transferase deficiency who presented in the neonatal period and review the current literature on this subject. Our patient was initially suspected to have distal renal tubular acidosis, and subsequently, a fasting test revealed severe metabolic ketoacidosis with normal blood glucose after 13 h which suggest a defect in ketolysis. In his cultured skin fibroblasts succinyl-CoA:acetoacetate transferase was deficient (residual activity 15%). Treatment in the acute phase consisted of sodium bicarbonate. At the present age of 9 years, psychomotor and physical development are within normal limits. CONCLUSION: Defects of ketolysis probably are underdiagnosed disorders and should be considered in infants and young children with persistent ketosis.
Subject(s)
Acetoacetates/metabolism , Acyl Coenzyme A/metabolism , Coenzyme A-Transferases/deficiency , Ketosis/enzymology , Metabolism, Inborn Errors/enzymology , Humans , Infant , Male , Metabolism, Inborn Errors/diagnosis , Metabolism, Inborn Errors/therapyABSTRACT
To clarify whether serum free fatty acid (FFA) is an inhibitor of extrathyroidal conversion (IEC) of thyroxine (T4) to thyronine (T3), we measured the concentration of FFA, IEC activity and thyroid hormones in normal subjects, acute ketotic children and children with low T3 syndrome due to nonthyroidal illness (NTI). Iodothyronine (I) 5'-deiodinase activity was assayed with reverse triiodothyronine (rT3) as substrate and liberated 125I-was measured. The IEC was determined by the inhibition of I 5'-deiodination by ether extract of sera or standard oleate solution. IEC values were represented as mM oleate. The serum concentration of FFA was 0.470 +/- 0.117 (SD) mM in 11 normal subjects, and it was significantly higher (1.242 +/- 0.248 mM; P < 0.01) in 10 acute ketotic children and in 7 samples from 6 NTI children (0.904 +/- 0.530 mM; P < 0.05). In contrast, there was no difference in IEC among three groups (normal subject, 0.451 +/- 0.069 mM; acute ketosis, 0.437 +/- 0.040 mM; NTI, 0.465 +/- 0.224 mM). No correlations were found between IEC activity and the serum FFA concentration or thyroid hormones in 28 samples from three groups. The sequential changes in serum thyroid hormones, FFA and IEC in 3 of 6 NTI children revealed no consistent relationship. Furthermore, one NTI child had significantly high IEC (> 1.000 mM) but its serum FFA (1.182 mM) was below the mean value for the acute ketotic group. These results indicate that 1) many NTI patients may bear no relation to IEC and 2) IEC may not be caused by serum FFA only but includes several factors.