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Presents the case of a febrile 33-year-old woman with type 1 diabetes mellitus. Symptoms including an infected ulcer on her right foot, lymphangitic spread to her knew, palpable groin nodes and an elevated leukocyte count with a neutrophilic shift; Diabetic complications including proliferative retinopathy and neuropathy; Discussion of drug treatment of renal insufficiency and calculation of creatinine clearance.

Several prostaglandin D (PGD) analogues have been synthesized, incorporating the following variations: (a) varying degrees of side-chain unsaturation, (b) C-9 hydroxy removed or in the unnatural 9 beta configuration, (c) metabolically stabilized analogues (e.g., 15-methyl, 16,16-dimethyl, 17-phenyl, etc.), and (d) delta 12 isomers resulting from decomposition of PGD2. With regard to their ability to inhibit adenosine diphosphate (ADP) induced human platelet aggregation: (a) PGD3 greater than or equal to PGD2 greater than PGD1 greater than 13,14-dihydro-PGD1, (b) the 9 beta- and 9-deoxy-PGD2 analogues are more potent than PGD2, (c) metabolically stabilized analogues with bulky substituents at or near C-15 have substantially reduced antiaggregatory activity relative to PGD2 and (d) the delta 12 isomers of PGD2 are much less active than PGD2.

Acetyl glyceryl ether phosphorylcholine (AGEPC) and leukotriene B4 (LTB4) induce concentration-dependent neutrophil aggregation. On a molar basis, LTB4 is approximately 10 to 100 times more potent than AGEPC. AGEPC-induced aggregation is attenuated by two inhibitors of arachidonate lipoxygenation, eicosatetraynoic acid and nordihydroguaiaretic acid, and to a lesser extent by the cyclooxygenase inhibitor, indomethacin. LTB4-induced aggregation is not readily reduced by the above inhibitors of arachidonic acid metabolism. Reverse phase high performance liquid chromatography, coupled with selective ion gas chromatography/mass spectrometry, shows that AGEPC stimulates neutrophils to synthesize sufficient LTB4 to account for the AGEPC response. In addition, the rate of LTB4 biosynthesis in response to AGEPC correlates well with the rate of AGEPC- and/or LTB4-induced neutrophils aggregation, and desensitization experiments indicate that AGEPC and LTB4 cross-desensitize. These data suggest that AGEPC-induced neutrophil aggregation may be mediated by LTB4.

Chemical analysis of intact leukotriene A4 showed that vertebrate albumins prolonged its aqueous half-life. At pH 7.4, leukotriene A4 hydrolyzed by first order reaction kinetics with rate constants inversely proportional to the albumin concentration. The stabilizing effect of albumin varied quantitatively among different species. Certain agents, such as warfarin, that interact with the site I binding region of albumin reversed its stabilizing effect. Sequestration and exposure of leukotriene A4 to a hydrophobic, alkaline microenvironment of albumin would account for the results. The amino acid sequences Lys-Ala-Trp-Ala-Val-Ala-Arg from residues 211-217 of human albumin or Lys-Ala-Trp-Ser-Val-Ala-Arg from residues 210-216 of bovine albumin are compatible with this requirement. The persistence of leukotriene A4 in the presence of albumin confirms and extends our recent observations on its uniform and predictable influence on eicosanoid stability. The significance of this influence is uncertain; however, albumin can no longer be viewed as inert considering its capacity to modify the stability of several, structurally diverse eicosanoids.

The chemotactic response of feline polymorphonuclear leukocytes (PMNs) to three types of chemoattractants was studied. Feline PMNs responded to leukotriene B4 as well as to agarose-activated autologous and homologous serum. However, no response was obtained to N-formylmethionylleucylphenylalanine (FMLP), and four similar peptides that activate the FMLP receptor (N-formylnorleucylleucylphenylalanine, N-formylmethionylphenylalanine, methionylleucylphenylalanine, and pepstatin). Thus, feline PMNs are similar to equine, porcine, bovine and canine PMNs which also do not respond chemotactically to these peptides.

The cytosolic glutathione S-transferases of rat liver have been fractionated by chromatofocusing into 10 distinct fractions based on their reactivity with 2,4-dinitrochlorobenzene. All these fractions were capable of generating leukotriene C4 (LTC4) from leukotriene A4 (LTA4) to some extent. An inhibitor of leukotriene synthesis, U-60,257, inhibited the activity of these enzymes. The cytosolic glutathione S-transferases of rat basophil leukemia (RBL) cells have been similarly fractionated. U-60,257 inhibited the activity of some of these fractions but not that of others. None of the fractions of the enzyme from RBL cells formed LTC4 from LTA4. The microsomal glutathione S-transferase from rat liver also produced LTC4 from LTA4. It differs from the microsomal LTC synthetase of RBL cells in at least two respects: (1) The enzyme from RBL cells did not react with chromophoric substrates like dinitrochlorobenzene while the enzyme from liver did react. (2) Triton X-100 potentiated the activity of the enzyme from basophil leukemia cells and solubilized it, while it inhibited the activity of the leukotriene-synthesizing enzyme in the rat liver preparation. These results, along with a distinctly different inhibitor profile, indicate that LTC synthetase is a new and distinct glutathione S-transferase.

The prostanoid 3-oxa-4,5,6-trinor-3,7-inter-m-phenylene-PGE1-amide (OI-PGE1-amide) has a prolonged duration of oral platelet aggregation inhibitory activity when compared to the parent free acid (OI-PGE1) in the rat. When incubated in rat plasma at 1 microgram/ml for 30 seconds prior to addition of ADP, OI-PGE1-amide inhibits in vitro rat platelet aggregation approximately 50%. OI-PGE1 inhibits at 1 ng/ml. Inhibition of platelet aggregation by plasma incubated with OI-PGE1-amide (1 microgram/ml) increases with time and the rate of this increase differs with species. Incubation of OI-PGE1 in plasma does not result in an increase of platelet inhibitory activity with time. The increase of platelet inhibitory activity was assumed to indicate hydrolysis of OI-PGE1-amide to the more active OI-PGE1. A compound, different from OI-PGE1-amide, was isolated by an ion exchange/silica gel separation sequence from an incubation of OI-PGE1-amide in rat plasma. It had potent platelet aggregation inhibitory activity. This material was shown to be OI-PGE1 by thin-layer chromatography, gas chromatography and mass spectral analysis. Studies with [3H]-OI-PGE1-amide confirmed the formation of OI-PGE1 in plasma incubations. Amide hydrolytic activity was significantly different between species, the rank order being: rat greater than guine pig greater than monkey = human greater than dog. This relationship corresponded with that determined by measuring the increase in platelet inhibitory activity with time in plasma incubations of OI-PGE1-amide reported above. Present data indicate that (a) OI-PGE1-amide is hydrolyzed to the parent acid by plasma enzymes of several species and (b) hydrolytic activity of plasma varies widely between species.

Rat basophil leukemia cell homogenates effectively catalyze the conversion of leukotriene A4 to a mixture of leukotrienes C4 and D4 in the presence of glutathione. These homogenates also catalyze the formation of adducts of halogenated nitrobenzene with glutathione, as determined spectrophotometrically. While all the classical glutathione S-transferase activity resides in the soluble fraction of the homogenates, the thiol ether leukotriene-generating activity is found in the particulate fraction. This "leukotriene C synthetase" activity has been solubilized from a crude high-speed particulate fraction by means of the nonionic detergent, Triton X-100. The solubilized enzyme is incapable of converting 2,4-dinitrochlorobenzene to a colored product in the presence of glutathione. Nor will it react with 3,4-dichloronitrobenzene. On the other hand, under optimal conditions, this enzyme preparation is capable of generating about 0.1 nmol leukotriene C mg protein-1 min-1 in a reaction which continues in linear fashion for at least 10 min. This dissociation in substrate specificity, as well as differences in the inhibition profile, distinguish the enzyme activity in the particulate fraction from rat basophil leukemia cell homogenates from the microsomal glutathione S-transferase which has been described in rat liver homogenates, suggesting that this "leukotriene C synthetase" is a new and unique enzyme.

Eighteen acetylenic fatty acids were tested as inhibitors of human platelet arachidonic acid 12-lipoxygenase. 4,7,10,13-Eicosatetraynoic (4,7,10,13-ETYA) acid emerged as the most potent compound. Additional experiments have shown that 4,7,10,13-ETYA selectively blocked the 12-lipoxygenase in washed human platelets with lesser activity against the cyclooxygenase. The ID50 value for lipoxygenase was 7.8 microM in comparison with an ID50 of 100 microM for the cyclooxygenase. The commonly used inhibitor 5,8,11,14-eicosatetraynoic acid inhibited both enzymes with equal potency. It appears that 4,7,10,13-ETYA may be a valuable lead for selective modulation of the 12-lipoxygenase pathway in platelet or other target tissues.

Our attempts to find a physiologically relevant means for inducing leukotriene synthesis in rat peritoneal mononuclear cells have thus far been unsuccessful in addition to the IgE-anti-IgE challenge which we previously reported, we have now tried human C3a and C5a as well as crude and semipurified fractions of the prostaglandin-generating factor of anaphylaxis. In each case, it was possible to show that these substances activated the cells even though no leukotrienes were formed. A cell-free system in which LTC + LTD formation can be studied was developed as a modification of published methods. Arachidonic acid and LTA4 served as precursors in this system in the presence of added glutathione. Calcium was required for LTC and LTD synthesis from arachidonic acid but was not required for the glutathione S-transferase terminal step in the synthesis. Using inhibitor profiles, substrate specificity for chromogenic substrates, and inactivation by selective antibodies, we tried to identify the subtype of the glutathione S-transferase in RBL cells. Although antibody to type E of the enzyme was most effective in neutralizing the enzyme activity, neither the substrate specificity nor the inhibition profiles agreed with the conclusion that the E-type enzyme was the major form in these cells. The effect of known inhibitors of glutathione S-transferase on the conversion of arachidonate to LTC and LTD was examined. Bilirubin, an inhibitor which binds to the enzyme and is not a substrate, was much more active in inhibiting LTC + LTD formation than were steroid sulfates, which were markedly less active in inhibiting this reaction. The inhibitory activities of the other compounds were similar on all substrates tested.

Allergic pulmonary reactions in vivo lead to airway constriction and mucous secretion, whereas in vitro lung anaphylaxis lead to mediator release and increased mucous glycoprotein secretion from cultured human airways. Using quantitation of radiolabeled mucous glycoprotein from cultured airways as a model for mucous release, the effects of two leukotrienes, LTC4 and LTD4, were assessed. BOth biosynthetic and synthetic LTC4 and LTD4 produced dose-related increases in mucous production at concentrations of 1 to 1,000 units/ml (20 to 20,000 pg [LTD4] and 24 to 24,000 pg [LTC4]/ml). These enhancing actions were seen in 11 of 11 lung cultures, and were significantly prevented by the specific SRS-A antagonist FPL 55712. Therefore, LTC4 and LTD4, two major components of the allergic mediator SRS-A, are potent mucous secretagogues and may possibly contribute to the mucous secretion observed during allergic reactions in vitro and in vivo.

Leukotrienes (C4, D4) have been shown to enhance mucus secretion in both isolated human airway tissue and intact canine trachea in vivo. They also have been implicated as putative mediators in several airways diseases. In previous canine studies the mucus enhancing effect of leukotriene-C4 was blocked by atropine, FLP 55,712, and hexamethonium but not by cutting the superior laryngeal and vagus nerves. We anesthetized mongrel dogs with chloralose (100 mg/kg) and urethane (500 mg/kg) and ventilated them on a pump. To visualize the secretions from submucosal glands, we exposed the mucosa of the upper trachea and coated its surface with powdered tantalum. Secretions from the glands formed elevation in the tantalum layer (hillocks) with time: the number of tracheal hillocks (an index of mucus secretion) was measured at one or more of the four time points on six dogs after each treatment of the treatment sequence: no LTC4, LTC4, no LTC4 + blocker, and LTC4 + blocker. The potential blocker was diphenhydramine, an H1 antagonist for histamine. LTC4 was injected into the cranial thyroid artery which directly feeds the tracheal segment. We observed hillocks through a dissecting microscope, and the number of hillocks per 1.2 cm2 were counted for a 1-4 min interval. In 6 dogs with 12 responses, LTC4 (10 micrograms) gave a positive response that was significantly different from control (p less than 0.01-0.05) at 2-4 min. Diphenhydramine (n = 6), 0.5 mg/kg, a dose which blocked a histamine challenge without blocking an acetylcholine challenge of secretion, gave a statistically significant (p less than 0.01-0.05) reduction in mucus secretion at 1-4 min. These results support the conclusion that leukotriene C4 induces mucus secretion in dogs that is blocked by prior diphenhydramine administration. This would indicate histamine has a role, but as yet an unknown mechanism in the action of leukotriene-C4 in enhancing mucus.

The chemical structure of prostaglandin X, the anti-aggregatory substance derived from prostaglandin endoperoxides, is 9-deoxy-6, 6alpha-epoxy-delta5-PGF1alpha. The stable compound formed when prostaglandin X undergoes a chemical transformation in biological systems in 6-keto-PGF1alpha. Prostaglandin X is stabilized in aqueous preparations by raising the pH to 8.5 or higher. The trivial name prostacyclin is proposed for 9-deoxy-6, 9alpha-epoxy-delta5-PGF1alpha.

In a survey of 311 residents of an urban community, 238 drinkers were classified by the beverage he or she drank most often. Beer, wine, and liquor drinkers, while differing by age, sex, and social class, did not differ with respect to other social characteristics. Four psychosocial stress factors were regressed on two consumption measures, with a different predictor of heavier drinking found to be significant for each beverage group. These findings in a cross-sectional study of normal drinkers parallel findings of studies of alcoholic and problems drinkers.

Both LTB4 and AGEPC stimulate PMN aggregation in a concentration-dependent manner. The lipoxygenase inhibitors ETYA and NDGA block AGEPC-induced but not LTB4-induced PMN aggregation. Agents that elevate PMN cyclic AMP levels block both LTB4-and AGEPC-induced aggregation. Paradoxically, shortly after aggregation is initiated by either AGEPC or LTB4, a transient spike in cyclic AMP levels is observed. Subsequent experiments show that LTB4 can directly elevate cyclic AMP in PMNs. Reverse-phase high-pressure liquid chromatography, coupled with selective ion gas chromatography/mass spectrometry, shows that AGEPC stimulates neutrophils to synthesize LTB4. These data suggest that AGEPC-induced neutrophil aggregation is mediated by LTB4.

The administration of tritiated piriprost, an inhibitor of leukotriene formation, to rats resulted in its rapid excretion. Some 90 percent of the initial dose was excreted in the feces and only five to six percent were recovered in the urine, regardless of the route of administration of the compound. The finding of significant, though low, residual activity in the liver even seven days after dosing (0.016 and 0.072% of dose in orally and iv-treated animals, respectively) suggested that piriprost may be bound by proteins in liver which play a role in detoxification. The finding that piriprost is a potent inhibitor of several partially purified cytosolic liver glutathione S-transferases ( EC 2.5.1.18) is consistent with this suspicion. Kinetic studies indicate that the inhibition may be competitive with the chromogenic substrate, chloro-2,4-dinitrobenzene (Ki 1-2 microM) and non-competitive with respect to glutathione when the second substrate was present at saturating concentration. Incubation of one to four micromolar radiolabeled tritiated piriprost with glutathione resulted in the gradual formation of a series of products which could be detected by high pressure liquid chromatography. The formation of these products was stimulated by the presence of glutathione S-transferase although the same products were also formed in the absence of the enzyme.

(5E)-6a-Carbaprostaglandin I2 (carbacyclin) was oxidized to (5E)-15-dehydro-6a-carbaprostaglandin I2 (15-dehydrocarbacyclin) by partially purified rhesus monkey lung prostaglandin dehydrogenase (PGDH). The (5E-15-dehydro-6a-carbaprostaglandin I2 was isolated by preparative thin-layer chromatography and identified by gas chromatography-mass spectrometry. A Lineweaver-Burke plot gave an apparent Km value of 2.9 microM and a Vmax of 35.7 nmoles carbacyclin oxidized/mg protein/min. These values are similar to previously reported Km and Vmax values for PGI2 and PGE1.