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PubMed1996

Preferential esterification of arachidonic acid into ethanolamine phospholipids in epithelial cells from ovine endometrium.

In sheep, the pulsatile release of prostaglandin F2 alpha by the endometrium is necessary to achieve luteolysis which occurs at the end of the oestrous cycle. The production of prostaglandins is known to depend upon the availability of arachidonic acid, the fatty acid precursor of prostaglandin biosynthesis. Consequently, the mechanisms controlling intracellular amounts of arachidonate may be involved in the regulation of prostaglandin synthesis. Since arachidonic acid is mostly found in phospholipids and the endometrial epithelium is the primary source of prostaglandin F2 alpha during luteolysis, the fate of arachidonic acid when incorporated into epithelial cells from the ovine uterus was investigated. Endometrial epithelial cells isolated from cyclic ewes at day 15 after oestrus were cultured in the presence of [3H]arachidonic acid. Incorporation and distribution of the radiolabelled arachidonic acid into the various phospholipid classes were examined using HPLC. We observed that ethanolamine glycerophospholipids contained 61% of the total tritiated arachidonic acid incorporated into cellular lipids, whereas phosphatidylinositols, phosphatidylcholines and phosphatidylserines contained 17%, 13% and 4.7%, respectively. In addition, the radioactivity measured within phosphatidylethanolamines was preferentially detected in the 1-alkenyl-2-acyl (44%) forms of ethanolamine phospholipids, also called plasmalogens. The kinetic study of arachidonic acid uptake into ethanolamine phospholipids showed that arachidonic acid was rapidly esterified into the diacyl forms and then uptake decreased, whereas the incorporation increased continuously into the plasmalogen forms for at least 24 h. These results demonstrate that the primary pool of esterified arachidonic acid is found in ethanolamine plasmalogens of epithelial cells from the ovine endometrium. The high arachidonate content of ethanolamine plasmalogens suggests that these phospholipids play a crucial role in the control of arachidonic acid availability and ultimately in the regulation of prostaglandin synthesis.

Animals↗
PubMed1996

Randomized trial of endoscopic injection sclerosis with ethanolamine oleate and ethanol for bleeding peptic ulcer.

BACKGROUND: Few studies have been done comparing ethanolamine oleate injection therapy with other sclerosing agents. Between September 1992 and August 1995, 78 consecutive patients presenting with a high-risk bleeding ulcer were randomized in a trial comparing endoscopic injection sclerotherapies with ethanolamine oleate and absolute ethanol. METHODS: The groups were well matched in terms of sex, age, clinical features, endoscopic findings, and non-steroidal anti-inflammatory drug usage. We recorded in a prospective randomized trial the initial success of endoscopy, the rebleeding rate, permanent hemostasis, treatment failures, the need for surgery, mortality, and factors related to mortality. RESULTS: Initial hemostasis was achieved in 90% (38 of 42) of the ethanolamine oleate group and in 97% (35 of 36) of the ethanol group, and permanent hemostasis in 88% (37 of 42) and 92% (33 of 36), respectively. The rebleeding rate, 7% and 8%; the emergency surgery rate, 10% and 6%; the transfusion requirement, 4.8 +/- 3.3 units and 4.0 +/- 3.0 units; and the 30-day mortality, 12% and 3%, did not differ significantly between the ethanolamine oleate and ethanol groups. Mortality was significantly related to shock at admission, duodenal site of the ulcer, ulcer size greater than 2 cm, and blood transfusion of over 5 units. CONCLUSION: Endoscopic injection sclerotherapies using ethanolamine oleate or absolute ethanol are safe and equally effective for bleeding peptic ulcers.

Blood Transfusion↗
PubMed1985

Complete co-purification of choline kinase and ethanolamine kinase from rat kidney and immunological evidence for both kinase activities residing on the same enzyme protein(s) in rat tissues.

Choline kinase and ethanolamine kinase were completely co-purified from rat kidney cytosol through acid treatment, ammonium sulfate fractionation, DEAE-cellulose column chromatography, Sephadex G-150 gel filtration followed by choline-Sepharose affinity chromatography. The final preparation appeared to be highly homogeneous with respect to both native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Ishidate, K., Nakagomi, K. and Nakazawa, Y. (1984) J. Biol. Chem. 259, 14706-14710). Throughout the purification steps, the ratio of ethanolamine kinase activity to choline kinase activity was almost constant in a range of 0.3-0.4, which strongly indicated that, in rat kidney, both activities could reside on a single enzyme protein. The rabbit polyclonal antibody raised against highly purified rat kidney choline (ethanolamine) kinase protein inhibited both choline and ethanolamine kinase activities in a parallel manner in crude enzyme preparations not only from rat kidney, but also from rat liver, lung and intestinal cytosols. The results, together with our previous findings, suggested strongly that, in rat tissues, at least large portions of both kinase activities are present on the same enzyme protein(s). The kinetic properties of both kinase reactions with the highly purified kidney enzyme were compared in some detail and the overall result suggested that choline kinase and ethanolamine kinase activities may not have a common active site on a single enzyme protein.

Adenosine Triphosphate↗
PubMed1988

Ethanolamine oleate versus absolute alcohol as a variceal sclerosant: a prospective, randomized, controlled trial.

Forty-seven patients with esophageal variceal bleeding were randomly allocated to undergo sclerotherapy on a 3 weekly schedule with either 5% ethanolamine oleate (23 patients) or absolute alcohol (24 patients), in an attempt to compare the efficacy and safety of the two sclerosants. Sclerotherapy with absolute alcohol eradicated esophageal varices significantly earlier compared with ethanolamine oleate (12.9 +/- 5.2 vs 22.3 +/- 8.2 wk, respectively, p less than 0.001). The mean number of injection courses and the mean amount of sclerosant required for variceal obliteration was also significantly (p less than 0.001) less in the alcohol-injected group. Although the total number of rebleeding episodes were significantly (p less than 0.05) less in the alcohol-injected group, the frequency of rebleeding was not significantly different between the two groups (20.8% vs 30.4%, respectively, p greater than 0.05). Two (8.1%) patients died due to rebleeding in the ethanolamine-injected group, whereas in the alcohol group, none died. There was no significant difference in the frequency of complications with the two sclerosants. Besides the relative ease of rapid injection due to its aqueous nature, alcohol is readily available and relatively economical (total cost of sclerosant per patient; alcohol US $0.50, ethanolamine US $60). In conclusion, absolute alcohol appears to be a useful alternative to 5% ethanolamine oleate as a variceal sclerosant.

Adult↗
PubMed1993

Albumin inhibits hemolysis of erythrocytes induced by ethanolamine oleate during endoscopic injection sclerotherapy.

In attempts to avoid hemolytic nephropathy following injection of 5% ethanolamine oleate during endoscopic injection sclerotherapy for esophageal varices, the relationship between serum levels of albumin and hemolysis induced by ethanolamine oleate was investigated. The rate of hemolysis at various concentrations of ethanolamine oleate and albumin was examined using a spectrophotometer in ten cirrhotic patients and five healthy volunteers (controls). Hemolysis induced by ethanol-amine oleate increased in an ethanolamine oleate concentration-dependent fashion (p < 0.01) but was dose-dependently inhibited by albumin (p < 0.05). The state of liver function was unrelated to the rate of hemolysis. The relationship between hemoglobinuria and serum albumin levels in seventy-nine cirrhotic patients with esophageal varices treated by endoscopic injection sclerotherapy with ethanolamine oleate was also examined. Hemoglobinuria was evident in 20 out of 24 patients (83.8%) in whom the serum albumin level was less than 3.0 g/dl, and in 24 out of 55 (43.6%) in whom it exceeded 3.0 g/dl, the difference being statistically significant (p < 0.01). On the day after endoscopic injection sclerotherapy, creatinine clearance fell from 81.6 +/- 33.8 m/l min to 60.1 +/- 31.4 ml/min in the hemoglobinuria-positive patients (p > 0.01) and two went into acute renal failure. The creatinine clearance ranged from 79.5 +/- 27.9 ml/min to 83.0 +/- 39.9 ml/min in the hemoglobinuria-negative patients (p < 0.1). In the light of this evidence we correct the serum albumin level cut off point to 3.0 g/dl prior to endoscopic injection sclerotherapy in order to maintain renal function.

Aged↗
PubMed1989

Ethanol alters the transfer of arachidonic acid to ethanolamine plasmalogens in C-6 glioma cells.

In this study, the effects of ethanol exposure on uptake and metabolism of arachidonic acid by C-6 glioma cells in culture was examined. Labeled arachidonic acid was effectively taken up by the phospholipids of these cells and radioactivity was initially incorporated into phosphatidylinositols and phosphatidylcholines, reaching a peak between 4 and 6 hours. However, the labeling of ethanolamine plasmalogens continued to show an increase with time after labeled arachidonic acid has been exhausted in the medium. Since over 90% of labeled arachidonic acid was already taken up by the cells after 4 hours of exposure, the continued increase in labeling of ethanolamine plasmalogens is attributed to a transacylation mechanism. Cells grown in 150 mM ethanol for 2 days did not show a change in the overall incorporation of labeled arachidonic acid into phospholipids but showed a significant increase in labeling of ethanolamine plasmalogens, which was marked by a concomitant decrease in labeling of phosphatidylcholines. Ethanol exposure also resulted in a significant increase in the transfer of labeled arachidonic acid to triacylglycerols. Changes in phospholipid and triacylglycerol labeling pattern positively correlated with increasing ethanol concentration from 75 to 300 mM. Besides, most ethanol effects were readily noticeable after 24 hours of exposure. These data suggest a specific effect of ethanol on promoting the transacylase process for biosynthesis of ethanolamine plasmalogens as well as the acyltransferase for biosynthesis of triacylglycerols.

Arachidonic Acid↗
PubMed1989

Identification of N-(2-propenal)ethanolamine as a urinary metabolite of malondialdehyde.

N-(2-propenal)ethanolamine was isolated from rat and human urine using anion exchange, cation exchange, size exclusion and high performance liquid chromatography. Acid hydrolysis of the isolate yielded malondialdehyde (MDA) and ethanolamine (E) in a 1:1 molar ratio. A 1:1 E-MDA adduct was synthesized and found to be chromatographically inseparable from the urinary metabolite. Its NMR and UV spectra and lack of fluorescence were consistent with those of an enaminal formed by a Schiff's base reaction. The identification in urine of an adduct of MDA with ethanolamine, and the previous identification of an adduct with serine, constitutes direct evidence for the oxidative decomposition in vivo of polyunsaturated fatty acids present in the relevant phospholipids. The absence in urine of MDA adducts with other alpha-amino compounds (at least in comparable amounts) indicates that the ethanolamine and serine derivatives are formed in situ and not as a result of reactions with MDA generated in enzymatic processes.

Animals↗
PubMed1984

A model for the common control of enzymes of ethanolamine catabolism in Escherichia coli.

By varying the composition of the growth medium and the genotype of the bacterial strain, five isoenzymes of CoA-dependent aldehyde dehydrogenase could be detected in Escherichia coli. Two isoenzymes (A, mol. wt 520 000; and B, mol. wt 370 000) were produced only in the presence of ethanolamine and vitamin (or coenzyme) B12 ('inducible isoenzymes'), whereas the other three isoenzymes (C, mol. wt 900 0000; D, mol. wt 120 000; and E, mol. wt 720 000) were produced only in the absence of ethanolamine and vitamin B12 ('repressible isoenzymes'). Partial purification and characterization of these isoenzymes revealed strong similarities, with respect to pH optima and substrate affinities, between isoenzymes within either of the two classes, but significant differences between the two classes. Mutant studies demonstrated that the relationships between the isoenzymes and between CoA-dependent aldehyde dehydrogenase and ethanolamine ammonia-lyase are both structural and regulatory in nature, and a two-operon model is proposed to account for the common control of the enzymes of ethanolamine catabolism in E. coli.

Aldehyde Dehydrogenase↗
PubMed1991

Effect of monomethylethanolamine, dimethylethanolamine, gangliosides, isoproterenol, and 2-hydroxyethylhydrazine on the conversion of ethanolamine to methylated products by cultured chick brain neurons.

The sequential methylation of ethanolamine and its phosphorylated derivatives has been studied with chick neurons in culture in the presence of several pharmacological agents. Incubation with [3H]ethanolamine in the presence of monomethylethanolamine and dimethylethanolamine indicated that in these neurons the preferential conversion to choline-containing compounds is via the methylation of phosphorylethanolamine. The possibility that there are two separate enzymes, i.e., one responsible for the methylation of water-soluble ethanolamine-containing compounds and another for the ethanolamine phospholipids, was examined with agents believed to influence these conversions. Incubation of neurons in the presence of a mixture of exogenous gangliosides at 10(-8) M and 10(-5) M concentrations showed that these neuritogenic compounds stimulate the methylation of phosphatidylethanolamine and decrease that of phosphorylethanolamine. The inhibitor of phosphatidylethanolamine methyltransferase (EC 2.1.1.17), 2-hydroxyethylhydrazine, decreased the conversion of phosphatidylethanolamine to phosphatidylcholine and increased that of phosphorylethanolamine to phosphorylcholine. The possible effects of adrenergic stimulation were studied by the incubation of neurons with isoproterenol at 10(-6) M and 10(-5) M concentrations. There was a reduction of phosphorylethanolamine methylation and a stimulation of that of phosphatidylethanolamine, and these effects were counteracted by the presence of 5 x 10(-5) M propranolol.

Animals↗
PubMed1995

Glutathione is required for maximal transcription of the cobalamin biosynthetic and 1,2-propanediol utilization (cob/pdu) regulon and for the catabolism of ethanolamine, 1,2-propanediol, and propionate in Salmonella typhimurium LT2.

Transcription of the cob/pdu regulon of Salmonella typhimurium is activated by the PocR regulatory protein in response to 1,2-propanediol (1,2-PDL) in the environment. Nutritional analysis and DNA sequencing confirmed that a strain defective in expression of the cob/pdu regulon in response to 1,2-PDL lacked a functional gshA gene. gshA encodes gamma-glutamylcysteine synthetase (L-glutamate:L-cysteine gamma-ligase [ADP forming]; EC 6.3.2.2), the enzyme that catalyzes the first step in the synthesis of glutathione (GSH). The DNA sequence of gshA was partially determined, and the location of gshA in the chromosome was established by two-factor crosses. P22 cotransduction of gshA with nearby markers showed 21% linkage to srl and 1% linkage to hyd; srl was 9% cotransducible with hyd. In light of these data, the gene order gshA srl hyd is suggested. The level of reduced thiols in the gshA strain was 87% lower than the levels measured in the wild-type strain in both aerobically and anaerobically grown cells. 1,2-PDL-dependent transcription of cob/pdu was studied by using M. Casadaban's Mu-lacZ fusions. In aerobically grown cells, transcription of a cbi-lacZ fusion (the cbi genes are the subset of cob genes that encode functions needed for the synthesis of the corrin ring) was 4-fold lower and transcription of a pdu-lacZ fusion was 10-fold lower in a gshA mutant than in the wild-type strain. Expression of the cob/pdu regulon in response to 1,2-PDL was restored when GSH was included in the medium. In anaerobically grown cells, cbi-lacZ transcription was only 0.4-fold lower than in the gshA+ strain; pdu-lacZ transcription was reduced only by 0.34-fold, despite the lower thiol levels in the mutant. cobA-lacZ transcription was used as negative control of gene whose transcription is not controlled by the PocR/1,2-PDL system; under both conditions, cobA transcription remained unaffected. The gshA mutant strain was unable to utilize 1,2-PDL, ethanolamine, or propionate as a carbon and energy source. The defect in ethanolamine utilization appears to be at the level of ethanolamine ammonia-lyase activity, not at the transcriptional level. Possible roles for GSH in ethanolamine, 1,2-PDL, and propionate catabolism are proposed and discussed.

Aerobiosis↗
PubMed1999

The 17-gene ethanolamine (eut) operon of Salmonella typhimurium encodes five homologues of carboxysome shell proteins.

The eut operon of Salmonella typhimurium encodes proteins involved in the cobalamin-dependent degradation of ethanolamine. Previous genetic analysis revealed six eut genes that are needed for aerobic use of ethanolamine; one (eutR), encodes a positive regulator which mediates induction of the operon by vitamin B12 plus ethanolamine. The DNA sequence of the eut operon included 17 genes, suggesting a more complex pathway than that revealed genetically. We have correlated an open reading frame in the sequence with each of the previously identified genes. Nonpolar insertion and deletion mutations made with the Tn10-derived transposable element T-POP showed that at least 10 of the 11 previously undetected eut genes have no Eut phenotype under the conditions tested. Of the dispensable eut genes, five encode apparent homologues of proteins that serve (in other organisms) as shell proteins of the carboxysome. This bacterial organelle, found in photosynthetic and sulfur-oxidizing bacteria, may contribute to CO2 fixation by concentrating CO2 and excluding oxygen. The presence of these homologues in the eut operon of Salmonella suggests that CO2 fixation may be a feature of ethanolamine catabolism in Salmonella.

Aerobiosis↗
PubMed2004

Evidence that a B12-adenosyl transferase is encoded within the ethanolamine operon of Salmonella enterica.

Adenosylcobalamin (Ado-B12) is both the cofactor and inducer of ethanolamine ammonia lyase (EA-lyase), a catabolic enzyme for ethanolamine. De novo synthesis of Ado-B12 by Salmonella enterica occurs only under anaerobic conditions. Therefore, aerobic growth on ethanolamine requires import of Ado-B12 or a precursor (CN-B12 or OH-B12) that can be adenosylated internally. Several known enzymes adenosylate corrinoids. The CobA enzyme transfers adenosine from ATP to a biosynthetic intermediate in de novo B12 synthesis and to imported CN-B12, OH-B12, or Cbi (a B12 precursor). The PduO adenosyl transferase is encoded in an operon (pdu) for cobalamin-dependent propanediol degradation and is induced by propanediol. Evidence is presented here that a third transferase (EutT) is encoded within the operon for ethanolamine utilization (eut). Surprisingly, these three transferases share no apparent sequence similarity. CobA produces sufficient Ado-B12 to initiate eut operon induction and to serve as a cofactor for EA-lyase when B12 levels are high. Once the eut operon is induced, the EutT transferase supplies more Ado-B12 during the period of high demand. Another protein encoded in the operon (EutA) protects EA-lyase from inhibition by CN-B12 but does so without adenosylation of this corrinoid.

Alkyl and Aryl Transferases↗
PubMed1986

Isolation and characterization of a Chinese hamster ovary cell line requiring ethanolamine or phosphatidylserine for growth and exhibiting defective phosphatidylserine synthase activity.

A mutant cell line (designated M.9.1.1) requiring ethanolamine for growth was derived from Chinese hamster ovary (CHO-K1) cells using 5-bromodeoxyuridine enrichment. The ethanolamine requirement was readily replaced by 20 microM phosphatidylserine and 10 microM lysophosphatidylethanolamine. When M.9.1.1 cells were supplemented with phosphatidyl[3H]serine it was rapidly taken up, and subsequently decarboxylated to form phosphatidyl[3H]ethanolamine. The incorporation of [3H]serine into phosphatidylserine in the mutant cells was 57% of that in the parental cells. Phosphatidylethanolamine synthesis from [3H]serine in the mutant cells was 35% of that in parental cells. When M.9.1.1 cells were deprived of ethanolamine for 48 h the level of phosphatidylserine decreased 34% and the level of phosphatidylethanolamine decreased 26% compared to parental cells. At the same time the rate of turnover of phosphatidylserine was reduced to half that found in parental cells. Examination of the enzymes of phosphatidylserine metabolism indicated defective phosphatidylserine synthase activity in the mutant. When exogenous phosphatidylcholine was used as the phospholipid substrate for the reaction the apparent kinetic constants were Vmax (mutant) = 5.7 pmol/min/mg protein and Vmax (parental) = 17.5 pmol/min/mg protein. Measurement of the back reaction (ATP-independent incorporation of choline into phospholipid) gave no detectable activity in the mutant cells. The data indicate that the phosphatidylcholine-dependent synthesis of phosphatidylserine is the primary lesion in M.9.1.1.

Animals↗
PubMed1978

The release of free ethanolamine in rat brain homogenates incubated in Krebs ringer.

Ethanolamine in mammalian brain is found chiefly in a lipid-bound form either as the diacyl phospholipid, phosphatidylethanolamine or as the plasmalogen, I-alk-11-enyl-2-acyl glycerophosphoethanolamine and to a lesser extent as the saturated ether analogue. The level of free ethanolamine in brain is very low, probably less than 40 nmol/g brain (Spanner & Ansell, 1977b) while that of phosphoethanolamine is about 1.0 mumol/g brain. Some time ago we found that if brain tissue was incubated in Krebs Ringer bicarbonate (pH 7.4) at 37 degrees, there was a steady release of free ethanolamine by the tissue. The following account is a summary of the findings from experiments designed to determine the source of the ethanolamine liberated.

Animals↗
PubMed1979

Ethanolamine kinase activity and compositions of diacylglycerols, phosphatidylcholines and phosphatidylethanolamines in livers of choline-deficient rats.

These experiments were performed to find the reasons for the increased concentrations of docosahexaenoyl phosphatidylethanolamines (PE) in livers of choline-deficient rats. We measured the activity of ethanolamine kinase, which catalyzes the first step in PE formation. We also measured the compositions of PE and phosphatidylcholines (PC) and concentrations and fatty acid compositions of diacylglycerols (DG), which are precursors of PE. Young male rats were fed for one week a low-methionine, choline-deficient diet, or the same diet supplemented with choline. Ethanolamine kinase activity was measured in liver cytosol (100,000 g supernatant). Fatty acids were measured in total liver diacylglycerols and in microsomal PE and PC. Ethanolamine kinase activities were equal in choline-deficient and choline-supplemented rats. Concentrations of DG were elevated 6-fold by choline deficiency. The percentage of docosahexaenoic acid (22:6n-3) in microsomal PE was nearly doubled by choline deficiency. Although the increased concentrations of PE in choline-deficient livers cannot be attributed to increased activity of ethanolamine kinase, the rate of PE formation probably was increased by increases in concentrations of its precursors, including DG. The disproportionate increase in 22:6n-3 PE probably was caused by a selective formation of PE from DG that contain 22:6n-3.

Animals↗
PubMed1977

Effects of deoxycholate and phospholipase A2 on choline and ethanolamine phosphotransferases of chicken brain microsomes.

Ethanolamine phosphotransferase (EC 2.7.8.1) and choline phosphotransferase (EC 2.7.8.2) activities were assayed in fresh microsomes from adult chicken brains with either diacylglycerols or alkylacylglycerols. Pretreatment of microsomes with 1.25 mM sodium deoxycholate, a concentration less than the critical micelle concentration, produced a slight inhibition of choline phosphotransferase activity. A deoxycholate concentration (5.0 mM) greater than the critical micelle concentration (3.0 mM) decreased the choline phosphotransferase activity by more than 70% but had no effect on ethanolamine phosphotransferase activity. Inclusion of 1.25 mM deoxycholate in the assay medium decreased choline phosphotransferase activity 35% but increased ethanolamine phosphotransferase activity 50%. The deoxycholate appeared to inactive the choline phosphotransferase. Phospholipase A2 (Vipera russelli) treatments of microsomes removed phosphoglycerides and decreased both phosphotransferase activities to a similar extent. Decreased activities are probably due to disruption of the membrane structure. Choline and ethanolamine phosphotransferase activities are apparently in different enzymes which lack specificity for the type of diglyceride. Thus, the systematic names should include 1,2-diradyl-sn-glycerol instead of 1,2-diacyl-sn-glycerol.

Animals↗
PubMed1996

Is the high propensity of ethanolamine plasmalogens to form non-lamellar lipid structures manifested in the properties of biomembranes?

Plasmalogens are glycerophospholipids characterized by an alk-1'-enylether bond in position sn-1 and an acyl bond in position sn-2. These ubiquitous etherlipids exhibit a different molecular structure as compared to diacyl phospholipids. The most peculiar change is a perpendicular orientation of the sn-2 acyl chain at all segments to the membrane surface. This extended conformation results in an effectively longer aliphatic chain in plasmalogen than in the diacyl analog. Moreover, the lack of the carbonyl oxygen in position sn-1 affects the hydrophilicity of the headgroup and allows stronger intermolecular hydrogen-bonding between the headgroups of the lipid. These properties favour the formation of non-lamellar structures which are expressed in the high affinity of ethanolamine plasmalogen to adopt the inverse hexagonal phase. Such structures may be involved in membrane processes, either temporarily, like in membrane fusion or locally, e.g. to affect the activity of membrane-bound proteins. The predominant distribution of ethanolamine plasmalogens in some cellular membranes like nerve tissues or plasma membranes and their distinctly different properties in model membranes as compared to diacyl phospholipids impose the question, whether these differences are also manifested in the heterogeneous environment of biological membranes. The integration of biophysical studies and biochemical findings clearly indicated that the high propensity of ethanolamine plasmalogen to form non-lamellar structures is reflected in several physiological functions. So far it seems to be evident that ethanolamine plasmalogens play an important role in maintaining the balance between bilayer and non-lamellar phases which is crucial for proper cell function. Furthermore, they are the major phospholipid component of inverse hexagonal phase inclusions in native retina and are able to mediate membrane fusion as demonstrated between neurotransmitter vesicles and presynaptic membranes.

Cell Membrane↗
PubMed2006

Comparison of polynomial and neural fuzzy models as applied to the ethanolamine pulping of vine shoots.

The influence of operational variables in the pulping of vine shoots by use of ethanolamine [viz. temperature (155-185 degrees C), cooking time (30-90min) and ethanolamine concentration (50-70% v/v)] on the properties of the resulting pulp (viz. yield, kappa index, viscosity and drainability) was studied. A central composite factorial design was used in conjunction with the software BMDP and ANFIS Edit Matlab 6.5 to develop polynomial and fuzzy neural models that reproduced the experimental results of the dependent variables with errors less than 10%. Both types of models are therefore effective with a view to simulating the ethanolamine pulping process. Based on the proposed equations, the best choice is to use values of the operational valuables resulting in near-optimal pulp properties while saving energy and immobilized capital on industrial facilities by using lower temperatures and shorter processing times. One combination leading to near-optimal properties with reduced costs is using a temperature of 180 degrees C and an ethanolamine concentration of 60% for 60min, to obtain pulp with a viscosity of 6.13% lower than the maximum value (932.8ml/g) and a drainability of 5.49% lower than the maximum value (71 (o)SR).

Conservation of Natural Resources↗