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E Oliw

Publications and source records attributed to E Oliw.

At least 19 recordsLinked to original sources
PubMed2000

Qualitative and quantitative analysis of lipoxygenase products in bovine corneal epithelium by liquid chromatography-mass spectrometry with an ion trap.

Electrospray ionization ion trap mass spectra of 5-, 12-, and 15-hydroperoxyeicosatetraenoic (HPETE), hydroxyeicosatetraenoic (HETE), and ketoeicosatetraenoic (KETE) acids were recorded. The HPETE were partly dehydrated to the corresponding KETE in the heated capillary of the mass spectrometer. 12-HPETE and 15-HPETE were also converted to KETE by collision-induced dissociation (CID) in the ion trap, whereas CID of 5-HPETE yielded little formation of 5-KETE. Subcellular fractions of bovine corneal epithelium were incubated with arachidonic acid (AA) and the metabolites were analyzed. 15-HETE and 12-HETE were consistently formed, whereas significant accumulation of HPETE and KETE was not detected. Biosynthesis of 12- and 15-HETE was quantified with octadeuterated 12-HETE and 15-HETE as internal standards. The average biosynthesis of 15-HETE and 12-HETE from 30 microM AA by the cytosol was 38 +/- 8 and below 3 ng/mg protein/30 min, respectively, which increased to 78 +/- 21 and 10 +/- 4 ng/mg protein/30 min in the presence of 1 mM free Ca2+. The microsomal biosynthesis was unaffected by Ca2+. The microsomes metabolized AA to 15-HETE as the main metabolite at a low protein concentration (0.3 mg/mL), whereas 12-HETE and 15-HETE were formed in a 2:1 ratio at a combined rate of 0.7 +/- 0.2 microg/mg protein/30 min at a high protein concentration (1.8 mg/mL). The level of 12-HETE in corneal epithelial cells was 50 +/- 13 pg/mg tissue, whereas the endogenous amount of 15-HETE was low or undetectable (<3 pg/mg tissue). Incubation of corneas for 20 min at 37 degrees C before processing selectively increased the amounts of 12-HETE in the epithelium fourfold to approximately 0.2 ng/mg tissue. We conclude that 12-HETE is the main endogenously formed lipoxygenase product of bovine corneal epithelium.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1999

cDNA cloning of 15-lipoxygenase type 2 and 12-lipoxygenases of bovine corneal epithelium.

Bovine corneal epithelium contains arachidonate 12- and 15-lipoxygenase activity, while human corneal epithelium contains only 15-lipoxygenase activity. Our purpose was to identify the corneal 12- and 15-lipoxygenase isozymes. We used cDNA cloning to isolate the amino acid coding nucleotide sequences of two bovine lipoxygenases. The translated sequence of one lipoxygenase was 82% identical with human 15-lipoxygenase type 2 and 75% identical with mouse 8-lipoxygenase, whereas the other translated nucleotide sequence was 87% identical with human 12-lipoxygenase of the platelet type. Expression of 15-lipoxygenase type 2 and platelet type 12-lipoxygenase mRNAs were detected by Northern analysis. In addition to these two lipoxygenases, 12-lipoxygenase of leukocyte (tracheal) type was detected by polymerase chain reaction (PCR), sequencing, and Northern analysis. Finally, PCR and sequencing suggested that human corneal epithelium contains 15-lipoxygenase types 1 and 2.

Amino Acid Sequence↗
PubMed1998

Manganese lipoxygenase. Discovery of a bis-allylic hydroperoxide as product and intermediate in a lipoxygenase reaction.

Linoleic acid was incubated with manganese lipoxygenase (Mn-LO) from the fungus Gäumannomyces graminis. The product consisted of (13R)-hydroperoxy-(9Z,11E)-octadecadienoic acid ((13R)-HPOD) and a new hydroperoxide, (11S)-hydroperoxy-(9Z,12Z)-octadecadienoic acid ((11S)-HPOD). Incubation of (11R)-[2H]- and (11S)-[2H]linoleic acids with Mn-LO led to the formation of hydroperoxides that largely retained and lost, respectively, the deuterium label. Conversion of the (11S)-deuteriolinoleic acid was accompanied by a primary isotope effect, which manifested itself in a strongly reduced rate of formation of hydroperoxides and in a time-dependent accumulation of deuterium in the unconverted substrate. These experiments indicated that the initial step catalyzed by Mn-LO consisted of abstraction of the pro-S hydrogen of linoleic acid to produce a linoleoyl radical. (11S)-HPOD was converted into (13R)-HPOD upon incubation with Mn-LO. The mechanism of this enzyme-catalyzed hydroperoxide rearrangement was studied in experiments carried out with 18O2 gas or 18O2-labeled hydroperoxides. Incubation of [11-18O2](11S)-HPOD with Mn-LO led to the formation of (13R)-HPOD, which retained 39-44% of the 18O label, whereas (11S)-HPOD incubated with Mn-LO under 18O2 produced (13R)-HPOD, which had incorporated 57% of 18O. Furthermore, analysis of the isotope content of (11S)-HPOD remaining unconverted in such incubations demonstrated that [11-18O2](11S)-HPOD suffered a time-dependent loss of 18O when exposed to Mn-LO, whereas (11S)-HPOD incorporated 18O when incubated with Mn-LO under 18O2. On the basis of these experiments, it was proposed that the conversion of (11S)-HPOD into (13R)-HPOD occurred in a non-concerted way by deoxygenation into a linoleoyl radical. Subsequent reoxygenation of this intermediate by dioxygen attack at C-13 produced (13R)-HPOD, whereas attack at C-11 regenerated (11S)-HPOD. The hydroperoxide rearrangement occurred by oxygen rebound, although, as demonstrated by the 18O experiments, the oxygen molecule released from (11S)-HPOD exchanged with surrounding molecular oxygen prior to its reincorporation.

Ascomycota↗
PubMed1997

[Selective inhibitors of cyclooxygenase-2. New agents against pain and inflammation].

Peripherally active analgesics are considered to exert their effect by blocking the enzyme, cyclo-oxygenase (COX), thus inhibiting the biosynthesis both of prostaglandins and of thromboxanes. It was recently found that there are two enzymes which can form prostaglandins: COX-1 and COX-2. Whereas COX-1 is normally expressed in many tissues, expression of COX-2 can be induced in response to inflammation. New experimental findings in 'knockout' mice have suggested that subgrouping of cyclo-oxygenases as 'good' (COC-1) and 'bad' (COX-2) may be inappropriate. COX-2 specific NSAIDs (non-steroidal anti-inflammatory drugs) may be potent antiinflammatory and analgesic agents with no serious side-effects, though this has yet to be confirmed in clinical trials.

Analgesics↗
PubMed1982

Urinary excretion of prostaglandin F2 alpha and 6-keto-prostaglandin F1 alpha during volume expansion in patients with glomerulonephritis.

Thirteen patients with active IgA glomerulonephritis (IgA GN), ten patients with a history of Henoch-Schönlein glomerulonephritis (HS GN) and nine healthy controls were studied during hydropenia (HP) and 3% volume expansion (VE) with isotonic saline. Clearance of inulin and para-aminohippurate, urinary excretion of Na, immunoreactive prostaglandin F2 alpha (PGF2 alpha) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were determined. The patients with a history of HS GN had normal blood pressure and renal function. As in the controls, the urinary excretion of PGF 2 alpha decreased and the excretion of 6-keto-PGF1 alpha increased during VE. In the patients with IgA GN the glomerular filtration rate (GFR) was normal, markedly reduced and supernormal. Five patients had hypertension and an increased NA excretion in relation to the GFR during VE. As a group, the patients with IgA GN increased their urinary excretion of 6-keto-PGF1 alpha during VE, while the excretion of PGF2 alpha did not change. In relation to the GFR, the urinary excretion of PGF2 alpha and 6-keto-PGF1 alpha was markedly increased in two patients with low GFR, which implies that these substances play a role in advanced renal disease. VE had little effect on PG excretion in these patients. In the hypertensive patients the urinary excretion of PGF2 alpha and 6-keto-PGF1 alpha was the same as in those with normal blood pressure. PGs are therefore not likely to mediate the increased natriuretic response to VE in hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

Relation of naproxen kinetics to effect on platelet prostaglandin release in men and dysmenorrheic women.

The purpose of our investigation was to determine kinetics of naproxen [(+)-6-methoxy-alpha-methyl-2-naphthaleneacetic acid] relative to its inhibition of PGF 2 alpha release during thrombin-induced platelet aggregation in man after a single oral dose of 250 or 500 mg. Naproxen and its metabolite 6-hydroxy-alpha-methyl-2-naphthaleneacetic acid were measured by high-performance, reversed-phase liquid chromatography with fluorimetric detection. PGF 2 alpha was measured by radioimmunoassay in platelet-rich plasma (PRP). Our subjects were four healthy adult men and five dysmenorrheic women. Peak concentrations of naproxen varied between 26 and 69 microgram/ml and half-lifes varied between 9.5 and 21.9 hr, mean = 16.4 hr +/- 4.4 (SD). Naproxen plasma protein binding exceeded 99.9%. The concentration of the metabolite was less than 1% of naproxen and followed the same plasma concentration profile as the parent compound. The based concentration of PGF 2 alpha varied between 0.13 and 6.3 ng/ml, mean = 1.5 +/- 1.9 ng/ml. With no exception, there was a marked decrease in the PGF 2 alpha concentration in thrombin-stimulated PRP during therapy, and concentration was inversely correlated to the total plasma naproxen concentration.

Adult↗
PubMed1981

Additive clinical effect of indomethacin suppositories during salicylate therapy in rheumatoid patients.

Twelve rheumatic patients were given 2.0 and 4.5 g acetylsalicylic acid daily in two 3-week periods. On days 13 and 20 of each period the patients took a suppository containing either placebo or 50 mg of indomethacin. The study was performed double-blind. Indomethacin had a significant additive effect during ASA therapy with 2 g daily as estimated by articular index and subjective ratings of pain and morning stiffness. On the 4.5 g ASA dose there was a significant improvement only for articular index. The patients experienced less pain during maintenance therapy with 4.5 g of ASA compared with 2.0 g daily. Both ASA doses induced complete inhibition of prostaglandin PGF2 alpha release from platelets. Thus the suppression of PGF2 alpha release does not reflect the therapeutic response of these drugs. Side effects observed comprised tinnitus, dizziness and gastritis. In 2 of the patients the aminotransferase levels increased, indicating hepatotoxicity. The protein binding of salicylate decreased with increasing salicylate concentration. As the dose was increased from 2.0 to 4.5 g/day the unbound concentration increased 5 to 24 times. This reflects the combined effect of capacity-limited metabolism and capacity-limited protein binding of salicylate.

Adult↗
PubMed1980

A radioimmunoassay for 6-keto-prostaglandin F1 alpha utilizing an antiserum against 6-methoxime-prostaglandin F1 alpha. Application to study renal in vitro synthesis of prostacyclin.

PGI2 and 6-keto-PGF1 alpha were converted to 6-methoxime-PGF1 alpha (6-MeON-PGF1 alpha) by treatment with methoxyamine HCl in acetate buffer. The formed 6-MeON-PGF1 alpha was measured by radioimmunoassay. Antisera were raised in rabbits after immunization against 6-MeON-PGF1 alpha-BSA conjugate. Diluted 1:20.000 to bind 50% of the tracer (3H-6-MeON-PGF1 alpha, 100 Ci/mmol), the antiserum cross reacted 0.8% with PGE2, 1% with PGF2 alpha and less than 0.2% with PGD2, PGF1 alpha, PGF2 beta and TXB2. The radioimmunoassay was used to estimate release of PGI2 and 6-keto-PGF1 alpha from chopped rabbit renal medulla and cortex incubated in Krebs-Ringer bicarbonate buffer (37 degrees C, 30 min). The 6-keto-PGF1 alpha radioimmunoassay was validated in biological samples by mass fragmentography. The chopped medulla (n = 5) released 38-+9 ng/g/min and the cortex (n = 5) 4.7-+2-0 ng/g/min, while the release of immunoreactive PGE2 (iPGE2) and iPGF2 alpha was 171-+26 and 74-+13 ng/g/min from the medulla and 4.3-+1.3 and 2.7-+0.3 ng/g/min from the cortex, respectively. The results confirm previous findings, which indicate that in the renal medulla prostaglandin endoperoxides are mainly transformed to prostaglandins, while in the cortex transformation to PGI2 seems to be of greater relative importance.

6-Ketoprostaglandin F1 alpha↗
PubMed1980

Prostaglandins and thromboxanes in amniotic fluid during rivanol-induced abortion and labour.

Abortion or delivery were induced by extra-amniotic instillation of Rivanol during the second trimester in twelve patients and during the third trimester in two patients with fetal death and one patient with fetal acrania. Serial sampling of amniotic fluid was performed through a transabdominal catheter and the levels of free arachidonic acid (AA), prostaglandin F2 alpha (PGF2 alpha), prostaglandin E2 (PGE2), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TXB2) were determined. The levels of AA, PGF2 alpha, PGE2, 6-keto-PGF1 alpha and TXB2 in amniotic fluid increased significantly during induction with the exception of AA in fetal death which was high and remained constant during induction. Furthermore, PGF2 alpha, 6-keto-PGF1 alpha and TXB2 were all significantly correlated to AA. These observations suggested that free AA is released during Rivanol-induction of abortion and labour giving an increased synthesis of PGF2 alpha, PGE2 prostacyclin and thromboxane A2 in the fetal membranes and the decidua but not in the fetus. This increase might be relevant for the initiation and progress of abortion and labour in these patients.

Abortion, Induced↗
PubMed1980

Renal prostaglandins and sodium balance in the rabbit: lack of effect of aspirin-like drugs.

Urinary prostaglandin E2 (PGE2) and PGF2 excretion was previously found to be inversely related to sodium intake in the rabbit. Renal prostaglandin (PG) synthesis might therefore be involved in the renal handling of sodium. This possibility was tested by studying sodium excretion during inhibition of renal PG synthesis with four different nonsteroidal anti-inflammatory drugs in unanaesthetized, female rabbits. The rabbits n = 5-6) were kept in metabolic cages and chronically maintained on different sodium containing diets. On a medium salt diet (0.4% NaCl), neither treatment with indomethacin (1.5 mg/kg x 2 or 3 mg/kg x 2) nor diclofenac (1.5 mg/kg x 2) for three days changed the urinary excretion of sodium and water although the mean excretion of immunoreactive PGE2 (iPGE2) and iPGF2 were reduced by between 43-78%. On a very low salt diet (0.05% NaCl), two days treatment with aspirin (30 mg/kg x 2), diclofenac (3 mg/kg x 2), indomethacin (3.5 mg/kg x 2) or naproxen (10 mg/kg x 2) did not alter sodium excretion in any significant direction. The mean urinary PGE2 and PGF2 excretion was reduced by 35-63% and 63-85%, respectively. These results do not support a major role of PGs in the chronic regulation of sodium balance in the rabbit. The possible influence of mineralocorticoids on renal PG synthesis was studied by administration of aldosterone (100 microgram/kg x 2) for two days to rabbits on a high salt diet (2% NaCl) and cancrenoate (10 mg/kg x 2), an aldosterone antagonist, to rabbits on the very low salt diet. However, neither drug significantly changed the urinary excretion of PGF2 alpha, indicating that renal PG synthesis is not influenced by mineralocorticoids in the rabbit.

Aldosterone↗
PubMed1979

Mass fragmentographic determination of prostaglandin F2 alpha in human and rabbit urine.

Analysis of prostaglandin F2 alpha (PGF2 alpha) in urine is a useful indicator of renal prostaglandin synthesis. A mass fragmentographic method for PGF2 alpha analysis in human urine was developed using [3,3,4,4-2H4]PGF2 alpha as an internal standard and carrier. PGF2 alpha was extracted from urine (20 ml) with chloroform, purified by preparative thin-layer chromatography and converted to the methyl ester trimethylsilyl ether before analysis by gas chromatography--mass spectrometry. The specificity of the urine analysis was demonstrated by retention time and the use of two pairs of fragments m/e 494/498 and 513/517 with the same results. The coefficient of variation for duplicate analysis averaged 12.6%, n = 17. Urine from recumbent women contained 4.9 +/- 2.6 (S.D.) ng/ml or 4.1 +/- 1.0 ng PGF2 alpha per mg creatinine (n = 10) with little diurnal variation. Male urine contained 5.0 +/- 2.7 (S.D.) ng/ml or 3.7 +/- 2.1 ng/mg creatinine (n = 10). Similar concentrations were found in boys and in girls. These observations indicate that urinary PGF2 alpha originates from the kidneys with little contribution from the male accessory sexual glands. This method can also be applied to analysis of PGF2 alpha in rabbit urine.

Adult↗