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PubMed1999

Enhanced rectal absorption of insulin-loaded Pluronic F-127 gels containing unsaturated fatty acids.

The objective of this study was to prepare and to evaluate Pluronic F-127 (PF127) gel containing unsaturated fatty acids such as oleic acid (18:1), eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6) as a potential formulation for rectal delivery of insulin. The hypoglycemic effect of insulin was examined following rectal administration of the various formulations in normal rats. Rectal insulin absorption was markedly enhanced, and marked hypoglycemia was induced by all PF127 gels (insulin dose, 5 U/kg) containing different unsaturated fatty acids. PF127 gels containing unsaturated fatty acids presented low tmax mean values indicating that the absorption of insulin occurred very rapidly in the rectum. The relative hypoglycemic efficacy of PF127 gel formulations containing fatty acids such as oleic acid, eicosapentaenoic (EPA) and docosahexaenoic (DHA) were 28.4+/-8.1, 26.8+/-14.3 and 23.1+/-5.7%, respectively. The finding demonstrated that 20% PF127 gels containing unsaturated fatty acids are potential formulations for rectal delivery of insulin.

Administration, Rectal↗
PubMed1995

Oleate and other long chain fatty acids stimulate low density lipoprotein receptor activity by enhancing acyl coenzyme A:cholesterol acyltransferase activity and altering intracellular regulatory cholesterol pools in cultured cells.

Modification of dietary fatty acid composition results in changes in plasma cholesterol levels in man. We examined the effect of in vitro fatty acid supplementation on low density lipoprotein (LDL) receptor activity in cultured cells and questioned whether changes were related to fatty acid-induced alterations in acyl-CoA: cholesterol acyltransferase (ACAT) activity. Preincubation of cultured cells (i.e. human skin fibroblasts, J774 macrophages, and HepG2 cells) with oleic acid (oleic acid:bovine serum albumin molar ratio 2:1) at 37 degrees C for longer than 2 h resulted in a 1.2- to 1.5-fold increase in LDL cell binding at 4 degrees C and LDL cell degradation at 37 degrees C. Scatchard analysis showed that oleic acid increased LDL receptor number but not LDL affinity (Kd). Fatty acid supplementation of J774 macrophages increased both LDL receptor activity and cholesteryl ester accumulation. The ACAT inhibitor, 58-035, eliminated both effects, and increased ACAT activity preceded stimulation of LDL receptor activity by 1-2 h. Supplementation of macrophages with triolein emulsion particles also increased LDL cell binding and degradation, and addition of cholesterol to the emulsions abolished this effect. Among fatty acids tested, oleate (18:1), arachidonate (20:4), and eicosapentanoate (20:5) demonstrated the greatest effects. We hypothesize that certain fatty acids delivered to cells either in free form, or as triglyceride, first increase cellular ACAT activity, which then causes a decrease in an intracellular free cholesterol pool, signaling a need for increased LDL receptor activity. This mechanism may play a role in the effect of certain dietary fatty acids on LDL metabolism in vivo.

Cells, Cultured↗
PubMed1994

Effect of intratracheal dexamethasone on oleic acid-induced lung injury in the rat.

The therapeutic efficacy of single-dose intratracheal dexamethasone (2.5 mg/kg) in oleic acid-induced acute lung injury in the rat was established by showing significant improvement in bronchoalveolar lavage parameters and lung compliance at 24 h after oleic acid as compared with animals not treated with oleic acid. An equivalent dose of intraperitoneal dexamethasone demonstrated no therapeutic benefit at 24 h after oleic acid. The therapeutic effect of this single-dose intratracheal dexamethasone regimen was accompanied by recovery to normal bronchoalveolar parameters and lung compliance at 7 days, in contrast to previous observations made with high-dose sustained intraperitoneal dexamethasone (4 mg/kg for 7 days). This improved benefit:toxicity ratio of intratracheal dexamethasone compared with systemic dexamethasone may be due to enhanced topical anti-inflammatory potency relative to systemic potency and toxicity.

Animals↗
PubMed2006

Protein kinase Czeta is required for oleic acid-induced secretion of glucagon-like peptide-1 by intestinal endocrine L cells.

Long-chain, monounsaturated fatty acids (FAs) stimulate secretion of the incretin hormone, glucagon-like peptide-1 (GLP-1) from the intestinal L cell. Because the atypical protein kinase C (PKC), PKCzeta, is involved in FA signaling in many cells, the role of PKCzeta in FA-induced GLP-1 secretion was investigated, using the murine GLUTag L cell line and primary rat intestinal L cells. GLUTag cells expressed mRNA for several PKC isoforms, including PKCzeta, and PKCzeta protein was localized throughout the cytoplasm in GLUTag and primary L cells as well as normal mouse and rat L cells. Treatment with oleic acid (150-1000 microm) for 2 h increased GLP-1 secretion (P < 0.001), and this was abrogated by the PKCzeta inhibitor ZI (P < 0.05) and PKCzeta small interfering RNA transfection (P < 0.05) but not inhibition of classical/novel PKC isoforms. Although most PKCzeta was localized in the particulate compartment of GLUTag cells, oleate treatment did not alter PKCzeta levels or activity in this cell fraction. GLUTag cells expressed mRNA for the Gq-coupled FA receptor GPR120; however, oleic acid did not induce any changes in Akt, MAPK, or calcium, and pretreatment with LY294002 and PD98059 to inhibit phosphatidylinositol 3-kinase and MAPK, respectively, did not prevent the effects of oleic acid. Finally, GLUTag cells also released GLP-1 in response to arachidonic acid (P < 0.001) but were not affected by other long-chain FAs. These findings demonstrate that PKCzeta is required for oleic acid-induced GLP-1 secretion. This enzyme may therefore serve as a therapeutic target to enhance GLP-1 release in type 2 diabetes.

Animals↗
PubMed2005

Insulin and leptin do not affect fatty acid uptake and metabolism in human placental choriocarcinoma (BeWo) cells.

Placental transport of long chain polyunsaturated fatty acids is important for fetal growth and development. In order to examine the effects of leptin and insulin on fatty acid uptake by the placenta, placental choriocarcinoma (BeWo) cells were used. BeWo cells were incubated for 5h at 37 degrees C in the absence or presence of different concentrations of insulin (0.6, 60, and 100 ng) or leptin (10 ng) with 200 microM of various radiolabeled fatty acids (docosahexaenoic acid, arachidonic acid, eicosapentaenoic acid, and oleic acid, mixed with 1:1 bovine serum albumin (fat free). After incubation, the uptake and distribution of these fatty acids into different cellular lipid fractions were determined. The uptakes of oleic, eicosapentaenoic, arachidonic, and docosahexaenoic acids were 15.36+/-4.1, 19.95+/-3.6, 28.56+/-8.1, and 62.25+/-9.5 nmol/mg of protein, respectively, in BeWo cells. Incubation of these cells with insulin (0.6 or 60 ng/ml) or leptin (10 ng/ml) did not significantly alter uptake of any of these fatty acids (P>0.5). Insulin or leptin also did not affect beta oxidation of fatty acids in these cells. In contrast, leptin (10 ng/ml) and insulin (0.60 ng/ml)) stimulated the uptake of oleic acid (7.4+/-2.3 nmol/mg protein) in human adipose cells, SGBS cells by 1.28- and 2.48-fold (P<0.05), respectively. The distribution of fatty acids in different cellular lipid fractions was also not affected by these hormones. Our data indicate that unlike adipose tissue, fatty acid uptake and metabolism in placental trophoblasts is not regulated by insulin or leptin.

Adipose Tissue↗
PubMed1996

Ultrasound-assisted synthesis of santalbic acid and a study of triacylglycerol species in Santalum album (Linn.) seed oil.

Methyl ricinoleate (1) was treated with bromine and the dibromo derivative (2) was reacted with ethanolic KOH under ultrasonic irradiation to give 12-hydroxy-octadec-9-ynoic acid upon acidification with dil. HCI. The latter compound was methylated with BF3/methanol to give methyl 12-hydroxy-octadec-9-ynoate (3). Compound 3 was treated with methanesulfonyl chloride in the presence of triethylamine in CH2Cl2 to give methyl 12-mesyloxy-octadec-9-ynoate (4). Reaction of methyl 12-mesyloxy-octadec-9-ynoate with aqueous KOH under ultrasonic irradiation (20 kHz) gave (11E)-octadecen-9-ynoic acid (5, santalbic acid, 40%) and (11Z)-octadecen-9-ynoic acid (6, 60%) on acidification with dil. HCI. These isomers were separated by urea fractionation. The 13C nuclear magnetic resonance (NMR) spectroscopic properties of the methyl ester and the triacylglycerol (TAG) esters of these enynoic fatty acid isomers were studied. The carbon shifts of the unsaturated carbon nuclei of the methyl ester of the E-isomer were unambiguously assigned as 88.547 (C-9), 79.287 (C-10), 109.760 (C-11), and 143.450 (C-12) ppm, while the unsaturated carbon shifts of the (Z)-enynoate isomer appeared at 94.277 (C-9), 77.561 (C-10), 109.297 (C-11), and 142.668 (C-12) ppm. In the 13C NMR spectral analysis of the TAG molecules of type AAA containing either the (Z)- or (E)-enyne fatty acid, the C-1 to C-6 carbon atoms on the alpha- and beta-acyl positions were differentiated. The unsaturated carbon atoms in the alpha- and beta-acyl chains were also resolved into two signals except that of the C-11 olefinic carbon. Sandal (Santalum album) wood seed oil (a source of santalbic acid) was separated by silica chromatography into three fractions. The least polar fraction (7.2 wt%) contained TAG which had a random distribution of saturated and unsaturated fatty acids, of which oleic acid (69%) was the predominant component. The second fraction (3.8 wt%) contained santalbic acid (58%) and oleic acid (28%) together with some other normal fatty acids. Santalbic acid in this fraction was found in both the alpha- and beta-acyl positions of the glycerol "backbone." The most polar fraction (89 wt%) consisted of TAG containing santalbic acid only. The distribution of the various fatty acids on the glycerol "backbone" was supported by the results from the 13C NMR spectroscopic analysis.

Carbon Isotopes↗
PubMed1995

Interaction of unsaturated fatty acids with the red blood cell Ca(2+)-ATPase. Studies with a novel photoactivatable probe.

Unsaturated fatty acids, such as oleic acid, increase both the affinity for Ca2+ and the maximum effect of the Ca(2+)-ATPase of red blood cells [Niggli et al. (1981) J. Biol. Chem. 256, 8588-8592]. With the aim of examining the structural and kinetic details of the interaction between unsaturated fatty acids and the enzyme, we designed and synthesized 8-(5'-azido-O-hexanoylsalicylamido)octanoic acid (AS86), a photoactivatable analogue of unsaturated fatty acids. AS86, interacting noncovalently with the enzyme, shares with oleic acid the following properties: (i) it binds reversibly to the plasma membrane Ca(2+)-ATPase; (ii) in the absence of calmodulin, AS86 shows a biphasic behavior; i.e., at low concentrations it increases the affinity for Ca2+ and the maximum velocity of the enzyme, while at higher concentrations it decreases the maximum velocity; (iii) in the presence of calmodulin, AS86 increases slightly the affinity for Ca2+ and decreases the maximum velocity of the Ca2+ pump; and (iv) AS86 inhibits the activity of the enzyme devoid of its calmodulin-binding domain after proteolysis. When the reagent is covalently bound to the native enzyme, and then activated by calmodulin, increasing amounts of AS86 decrease the maximum velocity along a hyperbolic curve without modifying the apparent affinity for Ca2+. These results could be explained by the eventual existence of two different kind of sites recognizing the reagent: one influencing the affinity for Ca2+ and the other inhibitory of the calmodulin effects. When covalently bound, AS86 exerts its inhibitory effects upon the enzyme lacking the calmodulin-binding domain, thus reflecting that this action is promoted by interaction with a site lying outside this region. The purified enzyme is susceptible to be tagged with 125I-AS86. Both the inhibitory effect on the calmodulin-dependent enzymic activity after covalent binding of AS86 and the photoadduct formation between the enzyme and 125I-AS86 are impaired by the presence of oleic acid in a concentration-dependent fashion. Recognition of photoreactive fatty acid analogues by the purified enzyme could be useful to provide further insight on the location of the interacting sites.

Adult↗
PubMed1996

Protective effect of interleukin-1 receptor antagonist on oleic acid-induced lung injury.

OBJECTIVE: To observe the changes of interleukin-1 (IL-1), nitric oxide (NO) and nitric oxide synthase (NOS) in mice with oleic acid-induced acute lung injury (ALI) and the protective effects of interleukin-1 receptor antagonist (IL-1ra). MATERIAL AND METHODS: Male Kunming mice were divided into control, oleic acid and IL-1ra groups. The control group mice were injected saline; the oleic acid group mice were injected oleic acid (0.2 ml/kg): and the IL-1ra group mice were injected the IL-1ra (20 mg/kg). Lung index, lung wet-to-dry weight ratio, and total protein, cell analysis, nitric oxide measurement, NOS activity in BALF, lung pathology examination were made after an hour of administration of drug. RESULTS: Preadministration of IL-1ra to the mouse with ALI decreased the lung index, lung wet-to-dry weight ratio and leakage of protein from pulmonary capillary, elevated PaO2, and attenuated lung histologic injury. It was found that in bronchoalveolar lavage fluid (BALF), NO amount and lung NOS activity increased in oleic acid group, BALF NO amount and lung NOS activity decreased obviously after given IL-1ra. CONCLUSIONS: This study demonstrated the protective effect of IL-1ra on oleic acid-induced lung injury, NO may participate in the pathological process of lung injury.

Animals↗
PubMed1990

Prone position reverses gravitational distribution of perfusion in dog lungs with oleic acid-induced injury.

Although oxygenation improves in patients with the adult respiratory distress syndrome and in animals with oleic acid- (OA) induced acute lung injury when they are turned from the supine to the prone position, the mechanism(s) by which this improvement occurs is not known. Several groups have speculated that this improvement results from preferential edema accumulation in the dorsal lung regions and redistribution of perfusion away from these regions when the patients are turned to the prone position. We used radiolabeled microspheres to measure the regional distribution of perfusion (Qr) to the dorsal, mid, and ventral lungs of eight dogs in vivo in the supine and prone positions, before and after inducing acute lung injury with OA, and correlated the Qr observed after injury with the degree of regional extravascular lung water (EVLWr). Before OA, Qr increased along the gravitational gradient when the animals were supine but was more uniformly distributed when they were prone. After OA, Qr again followed a gravitational gradient when the animals were supine but was preferentially distributed to the nondependent regions when they were prone. EVLWr was similar in all regions, regardless of whether OA was injected when the animals were supine or prone. The gravitational Qr gradient is markedly reduced in the prone position, both before and after lung injury. The prone position-induced improvement in oxygenation is not the result of redistribution of Qr away from areas in which edema preferentially develops.

Animals↗
PubMed2006

Oleic acid-associated bronchiolitis obliterans-organizing pneumonia in beagle dogs.

Accidental intra-airway exposure of dogs with pure oleic acid produced bronchiolitis obliterans and bronchopneumonia. Pulmonary changes included multifocal to coalescing necrosis of bronchioles and adjacent alveoli, hemorrhage, inflammation, and exudation of fibrin. Hyperplasia of bronchiolar and alveolar epithelial cells and proliferation of loose fibrovascular connective tissue formed polyps or plugs of variable size and shape. Polyps in the airways primarily consisted of fibroblasts with loose or myxoid stroma and were variably covered with attenuated epithelial cells. Some polyps had prominent vasculature, mixed inflammatory cell infiltration, and/or necrosis. Polyps or plugs variably effaced bronchioles and adjacent alveoli. The changes closely resembled human bronchiolitis obliterans-organizing pneumonia (BOOP). Controlled intra-airway delivery of oleic acid in dogs may be a potential animal model of obstructive pulmonary diseases such as BOOP or bronchiolitis obliterans.

Animals↗
PubMed1983

The effects of prophylactic expiratory positive airway pressure on the resolution of oleic acid-induced lung injury in dogs.

It is not known whether positive end-expiratory airway pressure (PEEP) merely improves gas exchange in patients with the adult respiratory distress syndrome (ARDS) or if it also affects the resolution of their lung injury. The present investigation was performed to determine whether expiratory positive airway pressure (EPAP), a form of PEEP, is prophylactic in preventing the lung injury induced by oleic acid in dogs or in enhancing its resolution. Arterial and mixed venous blood gases and functional residual capacity (FRC) were measured in 14 pairs of mongrel dogs with indwelling catheters and permanent tracheostomies. One member of each pair was treated with 10 cm H2O EPAP through a valve attached to the tracheostomy tube. Both dogs received 0.06 ml/kg oleic acid intravenously at hour 0. Measurements were made at three, 12, and 24 hours, when EPAP was discontinued, and over the next six days. Five dog pairs were sacrificed at 72 hours; the other surviving animals were sacrificed at 168 hours. FRC was higher at three, 12, and 24 hours in dogs receiving EPAP than in the untreated dogs. The arterial oxygen tension (PaO2) was higher and the venous admixture (Qva/Qt) was lower at three and 12 hours in the dogs receiving EPAP than in the untreated dogs. However, after 24 hours, no differences were noted between the two groups in FRC, PaO2, Qav/Qt, mortality, final lung compliance to initial lung compliance differences, lung water to dry lung weight ratios, or histology. It is concluded that EPAP improves gas exchange during its administration, but has no demonstrable prophylactic effect on the resolution of lung injury in the oleic acid model of human ARDS.

Animals↗
PubMed1989

Intralobular distribution of oleic acid-induced pulmonary edema in the pig. Evaluation by high-resolution CT.

The objective of this study was to elucidate the features of experimentally induced pulmonary edema at the lobular level, using high-resolution CT (HRCT) with pathological correlation. We selected the pig as the experimental animal because the pig has well-defined pulmonary lobules. Twelve Yorkshire pigs were included in this study. Five animals were used for studying normal anatomy of the pig lung. Pulmonary edema was induced by oleic acid infusion in 7 pigs. All computed tomographic (CT) scans were performed on a GE 9800 scanner, using 1.5 mm slice-thickness, 16 cm field of view with 512 X 512 matrix and bone reconstruction algorithm. The animals were killed after CT scans and the lungs were removed, inflated, fixed and dried, and subsequently sliced in sections which corresponded to the CT sections. Using CT images, specimen radiography, and histology, we studied the intralobular distribution of pulmonary edema in selected lobules of each animal. Oleic acid infusion caused multifocal hemorrhagic pulmonary edema within the pulmonary lobule. The distribution was uneven and areas surrounding the lobular bronchi were less involved. HRCT permits evaluation of morphological changes of oleic acid-induced pulmonary edema at the lobular level. The intralobular distribution of the lesions may provide additional information about the mechanism of permeability pulmonary edema.

Animals↗
PubMed1989

The effect of phospholipase A2 and cyclooxygenase inhibition on free fatty acids in the brain.

The levels of NEFA (oleic acid, palmitic acid, stearic acid, arachidonic acid) were studied in the brain cortex, hypothalamus and the brain stem of rat brain. Inhibition of phospholipase A2 by Delagil (Mepacrinium dichloratum CsL 3) decreased statistically significantly the values of arachidonic aci (-5.5%) in the brain cortex and the values of stearic acid (-11.2%) in the hypothalamua. The cyclooxygenase inhibition by aspirin led to a significant increase of palmitic acid (+12.7%), oleic acid (+18.7%) and arachidonic acid (+14.3%) in the hypothalamus. Total NEFA increased by 11.2%. A significant increase of palmitic acid (+26.9%), arachidonic acid (+33.9%) and of total NEFA (+22.9%) was evidenced in the brain stem. Delagil administered in combination with acetylsalicylic acid suppressed the NEFA increase observed after the application of acetylsalicylic acid alone. A statistically significant decrease was found in stearic acid (-12.6%) in the hypothalamus and in all studied NEFA in the brain stem (palmitic acid, -14.2% stearic acid -11.7%, oleic acid -3.8%, arachidonic acid -16.6% and total NEFA -11.8%).

Animals↗
PubMed1981

Effects of methylprednisolone on fatty acid induced edema in the dog lung.

In animals oleic acid induces a form of lung injury similar to that observed following fat embolization in humans. In the present study, canine lower left lung lobes were isolated, ventilated, and perfused at constant pressure with heparinized, autologous blood. Weight gain, in the absence of vascular volume change, in this preparation is a sensitive indicator of edema. One group of lobes was pretreated with 5.1 mg/gm lobe wt methylprednisolone before 1 microliter/kg body wt oleic acid. An untreated group given only oleic acid served as controls. Following oleic acid, the reduction in effective lobe compliance and blood PO2 and the increase in perfusate total protein concentration were similar in both groups. Rate of lobe weight gain following oleic acid was remarkably linear in both groups but significantly lower (p less than 0.05) in lobes pretreated with methylprednisolone. The latter group showed a total weight gain of 21% compared to 34% in the controls 3 hr after oleic acid challenge. We conclude that oleic acid induces a pulmonary edema in the absence of an elevation in hydrostatic pressure. Furthermore, rate of edema formation is attenuated by methylprednisolone pretreatment.

Animals↗
PubMed1986

Exocrine pancreatic function in oleic acid-induced pancreatic insufficiency in rats.

Pancreatic insufficiency was induced in rats by a single injection of 50 microliter oleic acid into the pancreatic duct over a period of 3 min. Exocrine tissue was destroyed within 3-6 days, and after 6 weeks the remaining pancreas equaled 2.7% of the original organ. The rats showed retardation of body weight in spite of normal food intake. After 7 weeks the fecal weight increased by 23%, and the fecal chymotrypsin activity decreased by 90% compared to controls. At this time plasma cholecystokinin (CCK) concentrations were significantly elevated. The amylase content in the remaining pancreas was reduced by 99%, and trypsin content was reduced by 93%. Unstimulated protein discharge from the remnant pancreas in vitro was threefold higher compared to secretion from control tissue. Thus a simple, reproducible model for inducing persistent pancreatic insufficiency was developed. To compensate for the loss of exocrine tissue, the remaining acinar cells adapt by a CCK-mediated increase in protein secretion.

Adaptation, Physiological↗
PubMed1998

Fatty acid composition of fertilization-failed human oocytes.

The aim of the study was to assess the fatty acid composition of human fertilization-failed oocytes. A total of 150 unfertilized oocytes from 43 women undergoing in-vitro fertilization (IVF) were analysed using capillary gas chromatography. The majority of fatty acids were saturated (79.22%), of which stearic (38.65%) and palmitic (32.66%) acids were the most abundant. Of the monounsaturated fatty acids (14.27%) oleic acid was the most abundant (9.77%). Polyunsaturated fatty acids comprised 6.50% of fatty acids, the n-6:n-3 ratio being 7.73. The ratio of eicosapentaenoic acid:docosahexaenoic acid was approximately 5. It is concluded that the most common fatty acids in human unfertilized oocytes are either saturated or monounsaturated fatty acids, whose main function is to provide an energy source. A number of differences in fatty acid composition were observed, in comparison with other biological samples. In particular, stearic and eicosapentaenoic acids were more prominent, and oleic and linoleic acids were less prominent; this may reflect some specific peculiarity of oocyte metabolism.

Adult↗
PubMed2001

Effects of vehicles and enhancers on transdermal delivery of melatonin.

For a more effective transdermal delivery of melatonin (MT), the effects of vehicles and enhancers on its skin permeation and lag time were evaluated. Skin permeation study was conducted in Franz diffusion cells using excised hairless mouse skins. MT was analyzed by HPLC. As vehicles, ethanol (EtOH), polyethylene glycol 400 (PEG), or propylene glycol (PG) was used alone or mixed with a phosphate buffer. Binary vehicles (EtOH/buffer, PEG/buffer, PG/buffer) showed different effects on the skin permeation of MT and its lag time. Compared with the buffer alone, the PEG/buffer shortened the lag time of MT but reduced its skin permeation. EtOH/buffer significantly increased the flux of MT but prolonged the lag time with the content of EtOH. PG/buffer did not affect the lag time but slightly increased the skin permeation of MT at the higher content of PG (> or =80%). These results indicate that the composition of vehicles exerts significant influence but it per se might have limitation in modulating the transdermal delivery of MT. Next, one tested whether fatty acids could more effectively enhance the skin permeation of MT and shorten its lag time. Given the influence of vehicles on both permeation and lag time, PG was used as a vehicle for fatty acids. The permeation-enhancing effects of saturated fatty acids increased in the following order: C10>C12>C14>C16>C18. The saturated fatty acid, however, did not significantly shorten the lag time regardless of the carbon chain length. Meanwhile, similar to saturated lauric acid (C12), unsaturated oleic acid (C18) dramatically enhanced the skin permeability coefficient of MT more than 950-fold over the effect of PG alone. Moreover, oleic acid showed the shortest lag time (2.1 h). The results suggest that oleic acid in a suitable vehicle could more effectively enhance the skin permeation of MT and shorten its lag time than did the vehicles of various compositions.

Animals↗
PubMed1984

Lipid binding activities of the P2 protein in peripheral nerve myelin.

Lipid binding activities of the P2 protein in peripheral nerve myelin were examined using retinoic acid, retinol and oleic acid as ligands. The P2 protein showed the specific binding affinity to both of retinoic acid and retinol. The binding site of these ligands was suggested to be similar. In addition, the high binding activity of the P2 protein with oleic acid was also observed. The ligands specificities of the P2 protein are clearly different from those of cellular retinoic acid binding protein (CRABP), cellular retinol binding protein (CRBP), and Z protein. In amino terminal sequence, however, the P2 protein contained considerable homologous structure to these lipid binding proteins. Therefore, the P2 protein and these lipid binding proteins may belong to a family of structurally related proteins evolved from a common ancestral gene.

Amino Acid Sequence↗