Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLYCERIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 109 records · Page 6Linked to original sources
PubMed1984

Phospholipid and glyceride biosynthesis in 2,4,5,2',4',5'-hexachlorobiphenyl-treated human skin fibroblasts.

2,4,5,2',4',5'-Hexachlorobiphenyl (HCB) was taken up by cultured human skin fibroblasts ( A61437 ; GM488 ). HCB caused enhanced incorporation of [2-14C]acetate into phospholipids and glycerides at low concentration and reduced incorporation at high concentrations. sn-[U-14C]Glycerol-3-phosphate incorporation into phospholipids was inhibited. No significant change in total cellular phospholipids was observed. Triglyceride cellular content was increased 29%. The observed stimulation and inhibition of phosphoglyceride synthesis are similar to results obtained with rat liver microsomes.

Cells, Cultured↗
PubMed1983

Accumulation of glyceride-modified pre-penicillinase of Bacillus licheniformis in Escherichia coli treated with globomycin.

The membrane penicillinase of Bacillus licheniformis is a glyceride-cysteine lipoprotein whose NH2 terminus is analogous to the major outer membrane lipoprotein of Escherichia coli. When E. coli cells producing B. licheniformis penicillinase were treated with the antibiotic, globomycin, a precursor of the penicillinase, pre-penicillinase, accumulated in the cell. It could be immunoprecipitated with anti-penicillinase antibodies; it contained palmitate; and one of its two cysteine residues was modified by glycerol. The action of globomycin, probably indirectly, also activates protease which acts differently on the pre-penicillinase than does the signal peptidase. The results strongly indicate that the pre-penicillinase is processed by the globomycin-sensitive signal peptidase in E. coli, and the modification of precursor by lipid precedes removal of the signal peptide as it does with the membrane lipoproteins of E. coli.

Anti-Bacterial Agents↗
PubMed1987

The effects of exercise on lipogenic enzyme activity and glyceride synthesis by liver homogenates of diabetic rats.

The purpose of this study was to determine if exercise ameliorates the elevated levels of triglycerides in diabetic rats and also to determine if the capacity of liver to synthesize glycerides correlates with changes in plasma triglyceride levels. Forty female rats were divided into four groups: sedentary control, sedentary diabetic, exercised control, and exercised diabetic. Diabetes was induced by intravenous injection of alloxan (40 mg/kg), and control rats were sham-dosed with physiologic saline. All rats remained sedentary in their cages for the first week after the injections. The exercised groups were exercised for seven consecutive days for 2 h/d at 20 m/min (0 grade). All rats were killed 24 hours after the last exercise bout. Blood glucose levels were significantly higher in the diabetic group than the nondiabetic counterparts, but exercise did not affect glucose levels in either the diabetic or nondiabetic groups. Exercise, however, significantly lowered plasma triglyceride and free fatty acid levels in both diabetic and nondiabetic rats. The activities of the five enzymes involved in fatty acid synthesis were all depressed in the diabetic rats compared to controls, and exercise had no effect on the activities of the enzymes. The capacity of liver to synthesize total lipids, diglycerides, or triglycerides was not different in the diabetic rats from that of nondiabetic rats, and exercise did not change that. Only phospholipid synthesis from glycerol-3-phosphate was affected by diabetes. It is concluded that exercise ameliorates the elevations in plasma triglyceride levels that result from diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

In vivo evaluation of an indomethacin monolithic, extended zero-order release hard-gelatin capsule formulation based on saturated polyglycolysed glycerides.

The sustained release properties of an indomethacin hard-gelatin capsule formulated with saturated polyglycolysed glycerides (Gelucire) were demonstrated in vivo. Indomethacin was selected as a model drug with very poor solubility in water and acidic media. It is known to exhibit high intersubject variability because of enterohepatic circulation. The formulation, which in vitro showed an erosion-controlled release, was compared in six human volunteers in the fed state by using a randomized cross-over design, to a standard multiple-unit diffusion-controlled pellet capsule. Close action period values (time duration with plasma levels higher than 0.5 micrograms/ml) were found for the test and the reference formulation (5.2 and 5.7 h). The time to reach peak t(max) appeared slightly shorter for the test preparation (1.75 h) than for the reference formulation (2.67 h), but the difference was not statistically significant because of the high intersubject variability (non-parametric Wilcoxon matched pair test). Again, due to the small number of subjects entered in the study (insufficient for a real bioequivalence study) equivalence could not be accepted in terms of extent and rate of absorption based on the decision procedures involving the 90% confidence interval and the two one-sided t-tests. The mean maximum plasma concentrations Cmax were 3.35 and 2.82 micrograms/ml for the test and the reference formulation respectively, with the corresponding values of the area under the plasma concentration-time curve AUC amounting to 10.14 and 11.38 micrograms h/ml. However, a simulation on 24 subjects (3 repetitions of the same data) would lead to bioequivalence of the two preparations. As for other corrosion-controlled forms, drug release from the proposed Gelucire formulation was very sensitive to hydrodynamic conditions, leading to poor in vitro-in vivo correlation, when comparison is made with a reference formulation characterized by a diffusion-controlled release. Finally, it was concluded that erosion-controlled release formulations are especially suitable for drugs, such as indomethacin, that have low solubility in water or acidic media. More generally, sustained release hard gelatin capsules with thermosetting excipients is very versatile and their preparation is very straightforward.

Adult↗
PubMed1986

In vivo modification of fatty acids and glycerides metabolism in response to 1,2,3,4,5,6-hexachlorocyclohexane and cythion exposure in the catfish, Clarias batrachus.

Specimens of either sex of the freshwater catfish, Clarias batrachus, were exposed to safe and sublethal concentrations of gamma-BHC (2 and 8 ppm) and cythion (1 and 4 ppm) for 4 weeks during different phases of annual reproductive cycle. Their effects on free fatty acids (FFA) and acyl glycerides, viz., monoglycerides (MG), diglycerides (DG), and triglycerides (TG), were studied in liver, plasma, gonads, and muscle. During the preparatory phase, both pesticides suppressed the levels of FFA and acylglycerides (MG, DG, and TG) in liver of either sex but had no effect on their levels in plasma, ovary, and muscle; however, FFA and TG were reduced in testis. Unlike the preparatory phase, in the prespawning phase different lipids responded variedly to the concentrations of both Cythion and gamma-BHC. In the female, FFA in liver and plasma was raised but in ovary and muscle it was decreased. Acylglycerides in studied tissues were also reduced except ovarian TG which was increased by both pesticides at safe concentrations. Contrary to this, in the male these lipids were raised in liver and testis. Moreover, during the spawning phase, these pesticides enhanced the hepatic FFA together with acylglycerides in the female but failed to elicit any change in their levels in the male. Plasma levels of FFA and TG were reduced in the female; however, in the male FFA was raised and TG remained unchanged. Ovarian FFA and TG were decreased and increased, respectively. During the postspawning phase, none of the lipid fractions could be affected in the male except hepatic FFA which was reduced; however, in the female TG along with FFA was decreased.

Animals↗
PubMed1977

High-performance liquid chromatographic analysis of partial glycerides and other technical lipid mixtures.

A high-performance liquid chromatographic (HPLC) technique for the analysis of partial glyceride mixtures is described and some technical details are discussed. Gradient elution HPLC with a "moving-wire" detector linked to a computer is used for quantitative analysis. The method described has been applied to the analysis of mono-, di- and triglyceride mixtures, food emulsifiers, certain seed fats, and technical products such as polymer additives.

Chromatography, High Pressure Liquid↗
PubMed1989

Rectal absorption enhancement of des-enkephalin-gamma-endorphin (DE gamma E) by medium-chain glycerides and EDTA in conscious rats.

The stability of the neuroleptic peptide des-enkephalin-gamma-endorphin (DE gamma E; Org 5878) in the rectal lumen and the rectal bioavailability of DE gamma E were investigated in conscious rats. Furthermore, the influence of peptidase inhibition, peptidase saturation, and absorption enhancement on DE gamma E bioavailability were evaluated. Na2EDTA (0.25%, w/v) prolonged the degradation half-life of DE gamma E in the ligated colon from 33 +/- 7 to 93 +/- 45 min. Without adjuvant, tritium-labeled DE gamma E was absorbed from the rat rectum to a very low extent (0-4%). After administration of an excess of unlabeled DE gamma E or with Na2EDTA, comparable results were obtained. The medium-chain glyceride preparation MGK markedly enhanced the rectal DE gamma E bioavailability, up to 8-20%, which was further increased to 10-44% by coadministration of Na2EDTA. No substantial influence of varying the rectal delivery rate was observed. The results suggest that absorption enhancement and enzyme inhibition both are essential for effective increase of rectal peptide bioavailability.

Absorption↗
PubMed1988

Enhanced membrane permeability to phenol red by medium-chain glycerides: studies on the membrane permeability and microviscosity.

To clarify the mechanism of the drug absorption enhancement by medium-chain glycerides (MCG), the changes in membrane permeability provoked by MCG were investigated with liposomal uptake experiments. Uptake of phenol red (PR) into liposomes increased with an increase in MCG content in the liposomal membrane, suggesting that PR absorption was enhanced in the "transcellular route." However, the apparent membranous microviscosity obtained in fluorescence depolarization studies tended to increase with the addition of MCG in both the hydrophobic core and the polar head regions of the liposomal membrane. Thus, an enhancement in membrane permeability caused by MCG was not accompanied by a decrease in the apparent membranous microviscosity.

Absorption↗
PubMed1994

Formulation and intestinal absorption enhancement evaluation of water-in-oil microemulsions incorporating medium-chain glycerides.

We developed self-emulsifying water-in-oil (w/o) microemulsions incorporating medium-chain glycerides and measured their conductance, viscosity, refractive index and particle size. Formulation of Calcein (a water-soluble marker molecule, MW = 623), or SK&F 106760 (a water-soluble RGD peptide, MW = 634) in a w/o microemulsion having a composition of Captex 355/Capmul MCM/Tween 80/Aqueous (65/22/10/3, % w/w), resulted in significant bioavailability enhancement in rats relative to their aqueous formulations. Upon intraduodenal administration the bioavailability was enhanced from 2% for Calcein in isotonic Tris, pH 7.4 to 45% in the microemulsion and from 0.5% for SK&F 106760 in physiological saline to 27% in the microemulsion formulation. The microemulsion did not induce gross changes in GI mucosa at a dosing volume of 3.3 ml/kg. These results suggest that water-in-oil microemulsion systems may be utilized for enhancement of intestinal drug absorption.

Absorptiometry, Photon↗
PubMed1994

Effect of medium-chain glycerides on physiological properties of rabbit intestinal epithelium in vitro.

Medium chain glycerides (MCGs) have been reported to enhance intestinal absorption of hydrophilic drugs. However, the mechanisms involved in absorption enhancement are not well understood. The effects of MCGs (CapMul MCM) on physiological properties of rabbit ileum and distal colon, including active ion transport, transepithelial resistance (Rt) and passive permeability, have been investigated in vitro. CapMul MCM inhibited active ion transport (measured as a decrease in short-circuit current, Isc) in both intestinal segments in a concentration-dependent manner. The inhibition of Isc was rapidly reversible (within 100 min) upon removal of CapMul MCM. The data indicate that CapMul MCM preferentially affected ion transport by villus cells in the ileum and surface cells in the distal colon. Ion transport in crypt cells in both segments was not significantly altered. Rt of the ileum was not significantly affected by 5% CapMul MCM, while mannitol transport was 6 fold enhanced. Treatment of distal colon with 1% CapMul MCM reduced Rt by 95%, while mannitol transport was 100 fold enhanced. In a parallel experiment, mucosal(m)-to-serosal(s) transport of cephalexin, a beta-lactam antibiotic, in the ileum was about 40% reduced in the presence of 5% CapMul MCM, whereas transport in the s-to-m direction was 2.5 fold enhanced. Treatment of the distal colon with 1% CapMul MCM resulted in 25 fold enhancement of cephalexin transport in either direction. These results suggest that absorption enhancement by MCGs results from an increased permeability of the intestine confined to the villus or surface epithelium.

Animals↗
PubMed1972

The regulation of glyceride synthesis in isolated white-fat cells. The effects of acetate, pyruvate, lactate, palmitate, electron-acceptors, uncoupling agents and oligomycin.

1. The incorporation of 5mm-[U-(14)C]glucose into glyceride fatty acids by fat cells from normal rats incubated in the presence of 20munits of insulin/ml was increased by acetate, pyruvate, palmitate, NNN'N'-tetramethyl-p-phenylenediamine, phenazine methosulphate, dinitrophenol, tetrachlorotrifluoromethyl benzimidazole and oligomycin. Lactate did not stimulate glucose incorporation into fatty acids. The effects of these agents were concentration-dependent. 2. In the presence of 5mm-glucose+insulin, [U-(14)C]acetate, [U-(14)C]pyruvate and [U-(14)C]lactate were incorporated into fatty acids in a concentration-dependent manner, thereby further increasing the total rate of fatty acid synthesis. 3. NNN'N'-tetramethyl-p-phenylenediamine decreased the incorporation of [U-(14)C]pyruvate into fatty acids in normal cells and increased the incorporation of [U-(14)C]lactate into fatty acids. 4. In fact cells from 72h-starved rats the stimulatory effects of NNN'N'-tetramethyl-p-phenylenediamine upon glucose and lactate incorporation into fatty acids were totally and partially abolished respectively whereas the stimulatory effects of acetate upon glucose incorporation were retained. 5. Combinations of the optimum concentrations of the substances that stimulate glucose incorporation into fatty acids were tested and compared. The effects of acetate+NNN'N'-tetramethyl-p-phenylenediamine and acetate+palmitate upon normal cells were additive. The effects of NNN'N'-tetramethyl-p-phenylenediamine+palmitate were not additive. It was found that total fatty acid synthesis in the presence of glucose was most effectively increased by raising the concentration of pyruvate in the incubation system. 6. The significance of these results in supporting the proposal that fatty acid synthesis from glucose in adipose tissue is a ;self-limiting process' is discussed.

Acetates↗
PubMed1995

Free fatty acids, neutral glycerides, and phosphoglycerides in transient focal cerebral ischemia.

Cerebral ischemia is known to cause an increase in levels of free fatty acids (FFAs) and diacylglycerols (DGs), although the mechanism(s) leading to these changes is not well understood. In this study, we examined FFA and DG levels along with those of other lipids in rats during and after transient focal cerebral ischemia induced by temporary occlusion of the right middle cerebral artery (MCA) and both common carotid arteries. During the duration of ischemia (15-60 min), there was a time-dependent increase (two- to 10-fold) in FFA levels in the right MCA cortex, whereas levels of DG and other lipids were not altered appreciably. FFA levels in right MCA cortex returned to near control values after reperfusion. However, following a 60-min ischemic insult, there was a second phase of FFA level increase that was evident after 16 h. The FFAs accumulated during the ischemia period were different from those after reperfusion, suggesting differences in mechanisms for their release. During the second phase of FFA release, there were increases in levels of DGs and triacylglycerols (TGs) with unusually high proportions of 20:4(n-6) and 22:6(n-3). The increases in FFA, DG, and TG levels were marked by a decrease in content of phosphoglycerides (PGs). It is interesting that the increases in levels of FFAs and neutral glycerides accounted only for 10% of the total PGs depleted. The lipid changes during this reperfusion period correlated well with the development of cortical infarct.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The production of bactericidal fatty acids from glycerides in staphylococcal abscesses.

Staphylococcal abscesses contain two types of lipids which are bactericidal for Staphylococcus aureus. These include a group of long chain unsaturated free fatty acids and another as yet unidentified lipid with unique properties. When abscess homogenates are incubated with S. aureus culture filtrates, the amount of bactericidal activity is increased. This phenomenon is called activation. To determine the source of increased bactericidal activity during activation, individual types of lipid were isolated from abscess homogenates and examined for their ability to be activated. Activation was found to result from the release of long chain unsaturated fatty acids from glycerides, presumably by the action of staphylococcal lipase.

Abscess↗
PubMed1988

Rate-controlled absorption enhancement of rectally administered cefazolin in rats by a glyceride mixture (MGK).

The enhancing effect of the medium chain glyceride preparation MGK on the rectal absorption of the cephalosporin antibiotic cefazolin sodium was evaluated in relation to the rate of delivery. Cefazolin sodium proved to be absorbed to a small extent (15 to 27%) after rectal administration without MGK. Bolus administration with MGK enhanced rate and extent of cefazolin sodium absorption, resulting in a bioavailability of 57 +/- 26%. Linear infusion of 3 mg cefazolin sodium with MGK in 32 min produced complete absorption of the antibiotic (102 +/- 7%), but absorption occurred slower in comparison with bolus delivery. The rate of administration proved to be an important variable of the absorption enhancing effect of MGK.

Administration, Rectal↗
PubMed1994

Rheological behaviour of saturated polyglycolysed glycerides.

Seven saturated polyglycolysed glycerides (Gelucires) of melting points varying from 42 to 53 degrees C and hydrophilic-lipophilic balance values from 2 to 14 were selected. Their rheological behaviour was determined by adjustment of the flow curves to the Ostwald power-law and by statistical assessment of the flow index. The flow of Gelucires was slightly shear thickening. This shear thickening rose when the temperature and the lipophilic specificity of the Gelucire increased. This behaviour accounted for a reorganization of the particles under the shear which became easier when the temperature increased and when the degree of condensation of the polyethylene glycol chains decreased with lipophilicity of the Gelucires.

Delayed-Action Preparations↗
PubMed1966

Handling of glycerides of acetic acid by rat small intestine in vitro.

1. When mono-, di- and triacetins are incubated with sacs of rat everted intestine, they enter the epithelial cells and are hydrolysed to free glycerol and acetic acid.2. The rate-limiting step in the process is the entry of glyceride into the epithelial cell.3. The three acetins enter the epithelial cell at the same rate, and the mechanism of this remains unknown.4. The acetate released appears in higher concentrations on the serosal side, and the relation of this to the mechanism for transfer of volatile fatty acids is discussed.5. It is not necessary to postulate a special mechanism for entry of volatile fatty acids into the cell.

Acetates↗
PubMed1988

Effect of medium chain glycerides on enteral and rectal absorption of beta-lactam and aminoglycoside antibiotics.

The rat enteral and rabbit rectal models were utilized to study the effect of Capmul (medium chain glycerides) on the absorption of a selection of beta-lactam and aminoglycoside antibiotics. All tested non-orally available beta-lactam antibiotics (cefamandole, cefotaxime, moxalactam, cefoxitin, mezlocillin, carumonam, penicillin G and amdinocillin) showed increased absorption enterally in rats and rectally in rabbits when formulated with Capmul. The orally available beta-lactam antibiotics, cephalexin and cephradine, were not enhanced in their enteral or rectal absorption by Capmul in the two model systems. Ampicillin absorption was enhanced rectally and enterally by Capmul. Rectal absorption of the aminoglycoside antibiotics, tobramycin and gentamycin, was enhanced by Capmul while enteral absorption was not.

Aminoglycosides↗
PubMed1990

Effect of medium-chain glycerides on the membrane transport of D-glucose and sulfanilic acid in the intestinal brush-border membrane vesicles.

To clarify the influence of medium-chain glycerides (MCG) on a biological membrane, we investigated the membrane transport of D-glucose and sulfanilic acid in the brush-border membrane (BBM) vesicles pretreated with MCG. The size distribution of the BBM vesicles determined by electron microscopic observation was not significantly different between the vesicles incorporated with MCG and those of the control. However, the amount of D-glucose taken up by the vesicles at an equilibrated stage (30 min) was significantly decreased in the MCG-treated ones based on unit content of protein. Based on these results we estimated the membrane transport of D-glucose and sulfanilic acid in consideration of vesiculation or filter-capturing efficiency in MCG-treated vesicles. The rates of Na+ gradient-independent D-glucose transport and sulfanilic acid transport were significantly greater in MCG-treated vesicles than in the control. On the other hand, the magnitude of overshooting effect in Na+ gradient-dependent uptake of D-glucose in MCG-treated vesicles was maintained similar to the control. Comparison of kinetic parameters for active D-glucose transport at different concentrations indicated that Km and Vmax were not significantly different between MCG-treated and the control vesicles. These results indicated that passive diffusion of D-glucose and sulfanilic acid was significantly increased but Na(+)-glucose cotransporter was not significantly changed by the incorporation of MCG in the intestinal BBM vesicles.

Benzenesulfonates↗