SEARCH · PubMed Health

Results for “Palmitates”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed2005

Alpha-synuclein gene deletion decreases brain palmitate uptake and alters the palmitate metabolism in the absence of alpha-synuclein palmitate binding.

Alpha-synuclein is an abundant protein in the central nervous system that is associated with a number of neurodegenerative disorders, including Parkinson's disease. Its physiological function is poorly understood, although recently it was proposed to function as a fatty acid binding protein. To better define a role for alpha-synuclein in brain fatty acid uptake and metabolism, we infused awake, wild-type, or alpha-synuclein gene-ablated mice with [1-(14)C]palmitic acid (16:0) and assessed fatty acid uptake and turnover kinetics in brain phospholipids. Alpha-synuclein deficiency decreased brain 16:0 uptake 35% and reduced its targeting to the organic fraction. The incorporation coefficient for 16:0 entering the brain acyl-CoA pool was significantly decreased 36% in alpha-synuclein gene-ablated mice. Because incorporation coefficients alone are not predictive of fatty acid turnover in individual phospholipid classes, we calculated kinetic values for 16:0 entering brain phospholipid pools. Alpha-synuclein deficiency decreased the incorporation rate and fractional turnover of 16:0 in a number of phospholipid classes, but also increased the incorporation rate and fractional turnover of 16:0 in the choline glycerophospholipids. No differences in incorporation rate or turnover were observed in liver phospholipids, confirming that these changes in lipid metabolism were brain specific. Using titration microcalorimetry, we observed no binding of 16:0 or oleic acid to alpha-synuclein in vitro. Thus, alpha-synuclein has effects on 16:0 uptake and metabolism similar to those of an FABP, but unlike FABP, it does not directly bind 16:0; hence, the mechanism underlying these effects is different from that of a classical FABP.

Acyl Coenzyme A↗

PubMed2000

Depot pipothiazine palmitate and undeclynate for schizophrenia.

BACKGROUND: Anti-psychotic drugs are usually given orally but compliance with medication given by this route may be difficult to quantify. The development of depot injections in the 1960s gave rise to extensive use of depots as a means of long-term maintenance treatment. Pipothiazine palmitate is a depot from the phenothiazine family of antipsychotic drugs. OBJECTIVES: To assess the effects of depot pipothiazine palmitate and undeclynate versus placebo, oral anti-psychotics and other depot antipsychotic preparations for people with schizophrenia in terms of clinical, social and economic outcomes. SEARCH STRATEGY: Relevant trials were identified by searching Biological Abstracts (1982-1998), Cochrane Library (Issue 2, 1998), Cochrane Schizophrenia Group's Register (June 1998), EMBASE (1980-1998), MEDLINE (1966-1998) and PsycLIT (1974-1998). References of all identified trials were also inspected for more studies and industry contacted. SELECTION CRITERIA: All clinical randomised trials focusing on people with schizophrenia where depot pipothiazine palmitate and undeclynate, oral anti-psychotics or other depot preparations were compared. DATA COLLECTION AND ANALYSIS: Studies were reliably selected, quality rated and data extracted. For dichotomous data Peto odds ratios (OR) with the 95% confidence intervals (CI) were estimated. Where possible, the number needed to treat statistic (NNT) was calculated. Analysis was by intention-to-treat. Normal continuous data were summated using the weighted mean difference (WMD). Scale data were presented only for those tools that had attained pre-specified levels of quality. MAIN RESULTS: Fourteen studies were included. When pipothiazine palmitate was compared to 'standard' oral antipsychotics no differences were found for outcomes of mental state, study attrition, behaviour and adverse effects (total randomised = 166). Pipothiazine palmitate was compared to other depot preparations in nine studies (n=455). Again no differences were identified for outcomes of global improvement, mental state, study attrition, behaviour and adverse effects. REVIEWER'S CONCLUSIONS: Although well-conducted and reported randomised trials are still needed to inform practice (no trial data exists reporting hospital and services outcomes, satisfaction with care and economics) pipothiazine palmitate is a viable choice for clinician and recipient of care. Data suggests it is not different to other depot antipsychotics.

Antipsychotic Agents↗

PubMed1964

ORIGIN OF PALMITIC ACID CARBON IN PALMITATES FORMED FROM HEXADECANE-1-C-14 AND TETRADECANE-1-C-14 BY MICROCOCCUS CERIFICANS.

Finnerty, W. R. (University of Iowa, Iowa City), and R. E. Kallio. Origin of palmitic acid carbon in palmitates formed from hexadecane-1-C(14) and tetradecane-1-C(14) by Micrococcus cerificans. J. Bacteriol. 87:1261-1265. 1964.-Degradation of the palmitic acid moiety of cetyl palmitate and myristyl palmitate formed from hexadecane-1-C(14) and tetradecane-1-C(14) by Micrococcus cerificans was carried out. The patterns of C(14) labeling in palmitic acid from cetyl palmitate showed that hexadecane is oxidized at the C(1) position, and cetyl alcohol and palmitic acid thus formed are directly esterified. Palmitic acid arising from tetradecane and esterified to tetradecanol appeared to have been synthesized by the addition of two carbon atoms to an existing 14-carbon atom skeleton. Considerable mixing of C(14) occurred in the C(1) and C(2) positions of palmitic acid thus synthesized.

Alkanes↗

PubMed2004

Palmitate increases nitric oxide synthase activity that is involved in palmitate-induced cell death in cardiomyocytes.

The objective of this study was to test the hypothesis that nitric oxide synthase (NOS) is subjected to regulatory control by palmitate, and that nitric oxide (NO) is operative in palmitate-induced cell death. Palmitate induced a significant ( p<0.05 ) concentration-dependent increase in NOS activity measured by the conversion of [(3)H]arginine to [3H]citrulline in embryonic chick cardiomyocytes. Cellular eNOS and iNOS, determined by immunocytochemistry, were increased by palmitate. Western blotting also showed that palmitate, 500 microM for 4h, significantly increased the amount of cellular of eNOS and iNOS by 36.2+/-6.5% ( p<0.001 ) and 38.4+/-14.4% ( p<0.05 ), respectively. The NOS inhibitor L-NAME significantly ( p<0.05 ) accentuated palmitate-induced cell death These data suggest that palmitate has a bifunctional effect on cell viability--in addition to loss of cell viability, palmitate stimulates NOS activity by inducing an increase in cellular eNOS and iNOS with the resultant NO production serving to protect cardiomyocytes from palmitate-induced cell death.

Animals↗

PubMed1998

Palmitic acid is associated with halorhodopsin as a free fatty acid. Radiolabeling of halorhodopsin with 3H-palmitic acid and chemical analysis of the reaction products of purified halorhodopsin with thiols and NaBH4.

Halorhodopsin, isolated from Halobacterium salinarium cells incubated with tritiated palmitic acid, co-elutes with labeled palmitate in phenylsepharose CL-4B chromatography. Halorhodopsin-bound 3H-palmitate is not readily displaced by prolonged exposure to a large excess of detergents and by re-chromatography of radiolabeled halorhodopsin on phenylsepharose. On other hand, the association of labeled palmitate with purified halorhodopsin is not resistant to denaturation induced either by isopropanol/hexane or by SDS gel electrophoresis. We have tested the hypothesis that tightly associated palmitate is bound to halorhodopsin through a thioester bond, which is unstable in denaturing conditions. Using GC/MS, we have analysed the reaction products of native halorhodopsin with specific thioester reagents, thiols and NaBH4, which are inactive on free fatty acids. The results of this analytical approach indicate that there is no thioester bond between halorhodopsin and palmitic acid and that palmitic acid is associated with halorhodopsin as a free fatty acid.

Bacteriorhodopsins↗

PubMed1998

Influence of malonyl-CoA and palmitate concentration on rate of palmitate oxidation in rat muscle.

5-Aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside (AICAR) is taken up by perfused skeletal muscle and phosphorylated to form 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuraosyl-5'-monopho sph ate (analog of 5'-AMP) with consequent activation of AMP-activated protein kinase, phosphorylation of acetyl-CoA carboxylase, decrease in malonyl-CoA, and increase in fatty acid oxidation. This study was designed to determine the effect of increasing levels of palmitate on the rate of fatty acid oxidation. Malonyl-CoA concentration was manipulated with AICAR at different palmitate concentrations. Rat hindlimbs were perfused with Krebs-Henseleit bicarbonate containing 4% bovine serum albumin, washed bovine red cells, 200 microU/ml insulin, 10 mM glucose, and different concentrations of palmitate (0. 1-1.0 mM) without or with AICAR (2.0 mM). Perfusion with medium containing AICAR was found to activate AMP-activated protein kinase in skeletal muscle, inactivate acetyl-CoA carboxylase, and decrease malonyl-CoA at all concentrations of palmitate. The rate of palmitate oxidation increased as a function of palmitate concentration in both the presence and absence of AICAR but was always higher in the presence of AICAR. These results provide additional evidence that malonyl-CoA is an important regulator of the rate of fatty acid oxidation at palmitate concentrations in the physiological range.

AMP-Activated Protein Kinases↗

PubMed1979

Metabolism of palmitate in perfused rat liver. Effect of low and high ethanol concentrations at various concentrations of palmitate in the perfusion medium.

1. The effect of ethanol on the metabolism of [1-(14)C]palmitate in rat liver was investigated in a single-pass perfusion system at concentrations of 10mm- or 80mm-ethanol and 0.2mm- or 1mm-palmitate. 2. After the perfusion the hepatic lipid was isolated in subcellular fractions. The two major fractions contained triacylglycerol from cytoplasmic lipid droplets and from endoplasmic reticulum plus Golgi apparatus respectively. 3. In experiments with 0.2mm-palmitate perfusion with 10mm- or 80mm-ethanol did not measurably increase the esterification, and the oxidation was markedly decreased and the fatty acid uptake was not affected. 4. Perfusion with ethanol, at 1mm-palmitate, increased the fatty acid uptake, increased esterification and decreased oxidation. The effects of 10mm- and 80mm-ethanol were similar. The incorporation of [1-(14)C]palmitate into triacylglycerol in cytoplasmic lipid droplets was not affected statistically significantly by ethanol. Ethanol increased the incorporation of [1-(14)C]palmitate into di- and tri-acylglycerol in the membranous fraction. Estimated chemically, the contents of di- and tri-acylglycerol were only slightly affected by ethanol. These results suggest that the effect of ethanol was to increase the turnover of fatty acids in triacylglycerol rather than to increase its accumulation. 5. The results indicate that an increased concentration of fatty acids is more important for the formation of acute fatty liver in fed rats than are the direct effects of ethanol on hepatic fatty acid metabolism.

Animals↗

PubMed1982

Stable isotope dilution method for measurement of palmitate content and labeled palmitate tracer enrichment in microliter plasma samples.

In studies where [1-13C]palmitic acid is employed as isotopic tracer in vivo, we have described a selected ion monitoring gas-liquid chromatography-mass spectrometry micro-method which allows plasma tracer enrichment as well as plasma palmitate content to be determined in the same 100-microliter sample through the use of [5,5,6,6-2H4]palmitic acid as assay internal standard. For standard solutions in the range equivalent to plasma palmitic acid concentrations of 10--2500 microM, assay precision was +/- 5%. For plasma samples in the physiologic range (approximately 30--200 microM palmitate) assay precision averaged better than +/- 2%. The use of the method is illustrated by measuring palmitate turnover in a 12-hr-old human infant.

Carbon Isotopes↗

PubMed1998

Solution structure of barley lipid transfer protein complexed with palmitate. Two different binding modes of palmitate in the homologous maize and barley nonspecific lipid transfer proteins.

The structure of a nonspecific lipid transfer protein from barley (ns-LTPbarley) in complex with palmitate has been determined by NMR spectroscopy. The structure has been compared to the structure of ns-LTPbarley in the absence of palmitate, to the structure of ns-LTPbarley in complex with palmitoyl coenzyme A, to the structure of ns-LTPmaize in its free form, and to the maize protein complexed with palmitate. Binding of palmitate only affects the structure of ns-LTPbarley moderately in contrast to the binding of palmitoyl coenzyme A, which leads to a considerable expansion of the protein. The modes of binding palmitate to the maize and barley protein are different. Although in neither case there are major conformational changes in the protein, the orientation of the palmitate in the two proteins is exactly opposite.

Antigens, Plant↗

PubMed2004

Determination of protein-bound palmitate turnover rates using a three-compartment model that formally incorporates [3H]palmitate recycling.

The observation that the palmitoylation state of certain proteins can be biologically modulated led to the proposal that it could, much like phosphorylation, be an important dynamic regulator of protein function. However, based on single-phase exponential decay analysis of data from [(3)H]palmitate pulse/chase experiments, the measured protein-bound palmitate turnover rates were often found to be too slow to account for rapid physiological responses. This paper reports that exponential decay does not adequately describe the results of such experiments because it fails to account for the recycling of [(3)H]palmitate from cellular lipids to palmitoyl CoA. Taking this recycling into account, a three-compartment model was used to deduce the time-dependent changes of cellular [(3)H]palmitoyl CoA and to infer the time course for the incorporation of [(3)H]palmitate into proteins. The validity of the inferences made by the model was checked against data obtained by metabolic labeling of endogenous HEK293 cell proteins. In addition, the model could account for reported anomalies, discrepancies, and apparently paradoxical observations obtained by traditional analysis of data from pulse/chase experiments. Including the recycling of cellular palmitate in the formal description of the system offers a new tool for quantitative assessment of protein-bound palmitate turnover rates. Through the re-evaluation of these rates, the model provides a means for the reassessment of the potential physiological implications of dynamic palmitoylation. The model may also be generally applicable to other areas of research where recycling of tracer is a concern.

Cell Division↗

PubMed1982

Isolation and identification of kahweol palmitate and cafestol palmitate as active constituents of green coffee beans that enhance glutathione S-transferase activity in the mouse.

Glutathione (GSH) S-transferase is a major detoxification enzyme system that catalyzes the binding of a variety of electrophiles, including reactive forms of chemical carcinogens, to GSH. Green coffee beans fed in the diet induced increased GSH S-transferase activity in the mucosa of the small intestine and in the liver of mice. A potent compound that induces increased GSH S-transferase activity was isolated from green coffee beans and identified as kahweol palmitate. The corresponding free alcohol, kahweol, and its synthetic monoacetate are also potent inducers of the activity of GSH S-transferase. A similar diterpene ester, cafestol palmitate, isolated from green coffee beans was active but less so than was kahweol palmitate. Likewise, the corresponding alcohol, cafestol, and its monoacetate showed moderate potency as inducers of increased GSH S-transferase activity. Kahweol palmitate and cafestol palmitate were extracted from green coffee beans into petroleum ether. The petroleum ether extract was fractionated by preparative normal-phase and reverse-phase liquid chromatographies successively. Final purification with silver nitrate-impregnated thin-layer chromatography yielded the pure palmitates of cafestol and kahweol. The structures were determined by examination of the spectroscopic data of the esters and their parent alcohols and by derivative comparison.

Animals↗

PubMed1996

Further observations on the measurement of fatty acid incorporation by erythrocyte ghosts to quantify unbound palmitate concentration in albumin-palmitate mixtures.

Advantage has been taken of the extensive and reversible incorporation of long-chain fatty acids by erythrocyte ghosts to characterize the interaction of tritium-labeled palmitic acid with human serum albumin (pH 7.4, 37 degrees C). A stoichiometric binding constant for 1:1 complex formation (K1) of 4.6 (+/-0.3) x 10(8) M-1 was obtained from experiments in which erythrocyte ghosts were the source of fatty acid. An essentially identical estimate of 4.1 (+/-0.7) x 10(8) M-1 was obtained from a second series of experiments in which the [3H]palmitate was included with the albumin in the aqueous phase. The magnitude of the present K1 estimate, which is three- to fivefold larger than most recently reported values, reflects binding measurements restricted to a very limited range of unbound palmitate concentration (-0.2 nM) to ensure that the ligand is essentially monomeric. This use of erythrocyte ghosts to quantify the palmitate-albumin interaction has reinforced the basic tenets of a published procedure [I. N. Bojesen, and E. Bojesen (1992) J. Lipid Res. 33, 1327-1334], the major virtue of which is its ability to provide a direct measure of the equilibrium concentration of unbound fatty acid in albumin-palmitate mixtures.

Binding Sites↗

PubMed1988

Stability of brain incorporation of plasma palmitate in unanesthetized rats of different ages, with appendix on palmitate model.

The unidirectional rate of incorporation of plasma palmitate, Jpalm, was measured in 43 brain regions of unanesthetized male Fischer-344 rats at 3, 12, 24 and 34 months of age. Jpalm was calculated from brain radioactivity 4 h after iv injection of [14C]palmitate, and from the integrated plasma specific activity of palmitate to 4 h. Jpalm was not related significantly to age (P greater than 0.05) in gray and white matter regions, nor was the white/gray ratio for Jpalm related to age (approximating 0.53 at all ages). These results demonstrate age invariance of incorporation of plasma palmitate into stable brain structures of the rat and suggest that turnover of brain lipids also is generally age invariant. A mathematical model for regional incorporation of plasma palmitate is given in an Appendix.

Aging↗

PubMed1979

Amniotic fluid palmitic acid/stearic acid ratios. Lecithin/sphingomyelin ratios and palmitic acid concentrations in the assessment of fetal lung maturity in diabetic pregnancies.

The lecithin/sphingomyelin (L/S) ratio, palmitic acid concentration and palmitic to stearic acid (P/S) ratio were estimated on samples of amniotic fluid obtained from 66 patients with diabetes. These were compared with similar estimates on amniotic fluid obtained from 127 non-diabetic patients. At 35 to 40 weeks, significant differences were observed between the L/S ratio and palmitic acid concentration in diabetics and non-diabetics, whereas the P/S ratio was similar in the two groups. The amniotic fluid L/S ratio, palmitic acid concentration, and P/S ratio were estimated on amniotic fluid obtained from 20 diabetic patients within 48 hours of induction, and the clinical outcome of the newborn infant was used to assess the predictive value of the three parameters. In 19 out of 20 diabetics the P/S ratio correctly predicted fetal lung maturity, whereas the palmitic acid concentration was correct in 12 patients and the L/S ratio in only 10 patients.

Amniotic Fluid↗

PubMed2003

Palmitic acid incorporation into intramuscular acylglycerols depends on both total and unbound to albumin palmitic acid concentration.

Palmitic acid incorporation into the intramuscular acylglycerols in rat skeletal muscles of different fiber types was investigated at various total and unbound to albumin concentrations by means of the hind-limb perfusion technique. It was found that at simultaneously increasing total and unbound to albumin palmitic acid concentrations in the perfusion medium the incorporation of palmitic acid into acylglycerols increased. However, when the concentration of palmitic acid not bound to albumin was kept constant and the total palmitic acid concentration was increased, the incorporation also increased although markedly less than under former conditions. The increase was most apparent in the muscles composed of slow-twitch oxidative and fast-twitch oxidative-glycolytic fibers where fatty acid uptake is the greatest. These findings suggest that fatty acid incorporation into intramuscular acylglycerols depends not only on the unbound to albumin fatty acid concentration but also, to some extent, on the total fatty acid concentration.

Animals↗

PubMed1979

Amniotic fluid lecithin/sphingomyelin ratio, palmitic acid, palmitic acid/stearic acid ratio, total cortisol, creatinine, and percentage of lipid-positive cells in assessment of fetal maturity and fetal pulmonary maturity: a comparison.

Lecithin/sphingomyelin (L/S) ratio, creatinine, percentage of lipid-positive cells, palmitic acid, palmitic acid/stearic acid (P/S) ratio, and total cortisol were analyzed as tests for fetal maturity and fetal pulmonary maturity in 164 samples of amniotic fluid from 121 patients. Fifty samples were taken within 72 hours of delivery. The best tests for fetal maturity (37 weeks) with differential percentages were L/S ratio, palmitic acid, and P/S ratio. In the assessment of fetal pulmonary maturity, we studied an additional 174 samples in which only L/S ratio, creatinine, and lipid-positive cells were analyzed. All tests showed a high predictive value of an immature (positive) result was much less for all six parameters; the three best tests were total cortisol (33%), lipid-positive cells (26%) and L/S ratio (14%).

Amniotic Fluid↗

PubMed2026

Weight and metabolic changes in patients with schizophrenia treated with paliperidone palmitate 6-month formulation versus paliperidone palmitate 3-month formulation: a post-hoc analysis.

OBJECTIVE: To determine the effect that paliperidone palmitate 6-month long-acting injectable formulation (PP6M) had on metabolic parameters including body weight (BW), and blood lipid profiles, a post-hoc analysis was conducted to assess changes in BW from baseline to the end of study based on age, body mass index (BMI), and changes in blood lipid profiles during a 12-month, phase 3, double-blind (DB) clinical study. Long term effects of PP6M on BW and BMI were further explored during a 24-month extension study in which participants were treated exclusively with PP6M. METHOD: In the 12-month DB phase, participants were randomized to receive PP6M or paliperidone palmitate 3-month long-acting injectable formulation (PP3M). The mean change in BW and abnormal weight percent change from baseline were calculated at endpoint by age, gender, and BMI. Additionally, treatment-emergent shifts from baseline for the four key lipid parameters (fasting low density lipoprotein [LDL], fasting triglycerides [TG], fasting total cholesterol [TC], and fasting high density lipoprotein [HDL]) during DB were assessed. Following this study, participants were given the opportunity to transition to a 24-month extension study and be treated with PP6M. The mean change and percent change in BW, and the mean change in BMI from DB baseline to the end of the extension study (36 months total) were calculated. RESULTS: Participants who were treated with PP6M showed numerically less weight gain, BMI, waist circumference, and more weight decrease compared to PP3M group during 12-month DB phase, though the proportion of participants reporting an abnormal change (≥7% change) in BW did not significantly differ between PP3M and PP6M. The weight differences were more pronounced in the younger age group (18-25 years) and those who were overweight (BMI: 25 to <30 kg/m2. Numerical differences in favor of PP6M were found in fasting blood lipids (HDL, LDL, TG, and TC). The changes in BW and BMI over time remained consistent throughout the 24-month extension, favoring PP6M in each instance. CONCLUSIONS: This post-hoc analysis demonstrated that PP6M was comparable to PP3M in terms of metabolic parameters; however, it may have a beneficial effect on weight gain, especially in young patients. TRIAL REGISTRATION: Post-Hoc Analysis of Studies NCT03345342 and NCT04072575 (ClinicalTrials.gov). Significant outcomes The findings from this study have highlighted that participants who were treated with the 6-month long-acting injectable formulation of paliperidone exhibited less weight gain during treatment overall, and significantly less weight gain in adolescents and young adults. Importantly, this trend continued over the course of long-term treatment, regardless of age. Participants treated with the 6-month formulation also had fewer shifts in blood lipids outside of the normal range and had more favorable changes in body mass index and waist circumference. These results suggest that when considering metabolic dysregulation as a factor in choosing a long-acting injectable antipsychotic, the 6-month formulation is a viable alternative to the 3-month formulation, particularly in younger patients with schizophrenia. Limitations Because this is a post hoc analysis and the study was not powered to test weight and metabolic changes, most endpoints were summarized descriptively and the statistical test was limited to the main endpoint (abnormal percent weight gain and loss).

Adult↗

PubMed1982

Erythrocyte survival and haematocrit values in rats after i.v. application of ethyl palmitate and methyl palmitate emulsions.

In the experiments on rats the effect of repeated application of ethyl palmitate emulsion (EP) and methyl palmitate emulsion (MP) on the survival rate of51Cr labelled erythrocytes and haematocrit values of the peripheral blood was studied. EP was applied in a total amount of 0.8 g, while MP due to its higher toxicity in a dose of 0.4 g per 100 g of body weight. The application of EP caused mild, though significant shortening of the survival period of the erythrocytes; the haematocrit values remained unchanged. Following application of MP no differences as compared to control animals could be found.

Animals↗