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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhalation of aerosols of ovalbumin in sensitized guinea pigs produced a marked, bronchoalveolar eosinophilia 24 hr after challenge. The lung eosinophilia was not prevented by the cyclooxygenase inhibitors, indomethacin or PAF antagonists (WEB-2086 and L-652731) but was inhibited by methylprednisolone, the 5-LO inhibitor, U-66858 and a series of structural analogs of LTB4, U-75302, U-77692, U-75485 and U-78489. The effectiveness of LTB4 antagonists but not PAF antagonists in vivo was consistent with in vitro studies in which LTB4 was shown to be far more chemotactic than PAF for guinea pig eosinophils. LTB4 elicited maximal directional migration of guinea pig eosinophils at concentrations from 10(-7) M to 10(-9) M while PAF showed no effect over the same concentration range. The structural analogs of LTB4 were shown to inhibit LTB4 induced chemotaxis of guinea pig eosinophils and produced a dose-related inhibition of binding of LTB4 to guinea pig eosinophil membranes. To add further proof to the hypothesis that LTB4 contributed to the antigen-induced lung eosinophilia we attempted to measure LTB4 release into BAL fluid immediately after and at various time points up to 24 hr after antigen inhalation. However, using a sensitive radioimmunoassay (detection limit 10 pg/ml) very low levels of LTB4 (24.9-67.9 pg/ml) or its metabolite, 20-OH LTB4 (24.9-98.2 pg/ml) were detected in BAL fluid and these levels did not increase significantly following antigen provocation. Inhalation of LTB4 aerosols in unsensitized Brown-Norway rats or inhalation of aerosols of ovalbumin in sensitized Brown-Norway rats also produced a marked "late-phase" eosinophil-rich influx of inflammatory cells into the lungs. The lung eosinophilia in the rat was prevented by two structurally unrelated leukotriene B4 (LTB4) antagonists, U-75302 and Ly255283. These data implicate LTB4 as a mediator of allergen-induced bronchopulmonary eosinophilia. Leukotriene B4 antagonists may provide leads for the development of compounds which inhibit the chronic airway inflammation associated with asthma in man.
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PMID:Contribution of leukotriene B4 to airway inflammation and the effect of antagonists. 165 82

Cerebral ischemia, induced in rats by occlusion of the middle cerebral artery resulted in infarcts affecting the basal ganglia and adjacent frontoparietal cortex. Resting oxygen consumption was similar for sham-operated and ischaemic rats immediately after surgery but was elevated in the latter group (peak value 18-21% above controls) 5-6 h post occlusion. By 24 h, these values had returned to control levels. The increase in VO2 was inhibited by injection of the beta-adrenergic antagonist propranolol but was unaffected by injection of the cyclooxygenase inhibitor ibuprofen. The thermogenic activity of brown adipose tissue was assessed from in vitro binding of guanosine diphosphate to mitochondria isolated from intact and surgically denervated lobes of sham-operated and ischemic rats, 6 h after surgery. Brown adipose tissue specific guanosine diphosphate (GDP) binding was elevated by 86% in intact tissue from ischemic compared with sham-operated rats but was identical in denervated tissue from the two groups. Brown adipose tissue activity correlated with resting oxygen consumption in the ischemic group (r = 0.85, p less than 0.01) but not in controls (r = -0.35, NS). Thus occlusion of the middle cerebral artery in the rat may provide a representative model for both stroke and head injury in man. It is associated with a transient increase in metabolic rate and by sympathetically mediated activation of brown adipose tissue in the rat.
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PMID:Sympathetically mediated hypermetabolic response to cerebral ischemia in the rat. 207 25

As previously reported, acute cyclosporine-induced nephrotoxicity is characterized by a decline in glomerular filtration rate and a selective intrarenal production of the vasoconstrictor thromboxane (TxA2), but not vasodilator prostaglandin E2 (PGE2), or prostacyclin (PGI2), cyclooxygenase metabolites. Fish oils (FO), that are rich in n-3 polyunsaturated fatty acids have a high affinity for cyclooxygenase but serve as poor substrate inhibit TxA2 synthesis. We have shown that when FO replaces olive oil (OO) as the vehicle for CsA, CsA-induced nephrotoxicity and increased TxA2 synthesis are obviated in rodent models. In this study, we demonstrate that the FO vehicle for CsA does not compromise CsA's immunosuppressive properties as deduced from studies of a delayed-type hypersensitivity (DTH) model in BALB/c mice and in a rat heart transplant model. In fact, concurrent FO administration with CsA actually enhances immunosuppression. A dose of CsA incapable of blunting DTH when injected in OO was suppressive when given in FO. Administration of as little as 0.05 ml of FO vehicle potentiated the suppressive action of CsA. In addition, nonconcurrent dietary supplementation of FO in animals receiving CsA caused an increase in the immunosuppressive action of CsA in DTH. FO alone reduced DTH as compared with OO, but was far less effective than CsA plus FO. Furthermore, doses of CsA (5 mg/kg/day or 1.5 mg/kg/day), which are subtherapeutic when administered with OO, prolonged engraftment of Lewis recipients of Lewis x Brown-Norway F1 hearts when CsA was solubilized with FO. These studies indicate that concurrent administration of CsA and FO potentiates the activity of CsA and thus increases its therapeutic index. Thus, CsA plus FO is potentially a safe, potent antirejection therapy worthy of clinical testing, especially insofar as FO prevents CsA-induced acute nephrotoxicity in the rodent.
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PMID:Enhancement of immunosuppression by substitution of fish oil for olive oil as a vehicle for cyclosporine. 266 42

A series of N-(2-benzoylphenyl)alanine derivatives were synthesized and tested for antiinflammatory activity in the Evans blue-carrageenan induced pleural effusion assay. The target compounds were envisioned to bind to a receptor site on the cyclooxygenase enzyme by a mechanism first proposed by Appleton and Brown. Of the 21 compounds prepared, two were found to be one-tenth as potent as indomethacin in the pleurisy model and one compound was tested and found to be weakly active in the adjuvant arthritis model.
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PMID:Antiinflammatory activity of N-(2-benzoylphenyl)alanine derivatives. 648 68

First, it is shown that it is not yet possible to outline a generally valid receptor model for the non-steroidal anti-inflammatory agents. This is demonstrated by three examples of receptor models, namely by the model according to Shen, by the receptor concept of Appleton and Brown, and by the concept concerning chelate complex formation between NSA and heme iron of the cyclooxygenase complex according to Peterson et al. This means that the "custom-made" synthesis of NSA with, perhaps, quantitatively and qualitatively better properties is not yet possible. On the basis of this statement, QSAR investigations may be justified in order to optimize known NSA. In this paper, QSAR calculations on 21 fenamate derivatives are reported. For this, both the multivariate and the univariate Hansch Analysis were used. Altogether, 16 approaches to QSAR has been performed using 1 - 4 biological and 3 - 19 physico-chemical parameters, respectively, with 7 - 21 objects. In all cases a dominating influence of pi has been indicated. Other physico-chemical parameters seemed to be of less importance, e. g., sigma, Es, log xi MR, MV, parachor, and Verloop's steric constants. Possible new fenamate structures of higher biological activity are briefly discussed.
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PMID:Structure-activity relationship in nonsteroidal antiinflammatory agents, including QSAR in fenamate derivatives. 681 Jun 62

Allergen challenge of sensitized Brown-Norway (BN) rats results in increased excretion of cysteinyl-leukotrienes (cLTs) in bile. It is unclear whether this reflects an increased capacity of lung cells to synthesize 5-lipoxygenase products, and, if so, which cells are of primary importance. We have examined the effects of allergen challenge on the capacity of a mixture of isolated lung cells from ovalbumin (OA)-sensitized BN rats to synthesize LTs and other eicosanoids. Cells were isolated by enzymatic digestion of lung tissue before and either 6 or 24 h after challenge of sensitized rats with either OA or saline. A23187-induced synthesis of eicosanoids by these cells was measured using high-pressure liquid chromatography. OA challenge resulted in a significant influx of neutrophils into the lungs and a significant increase in the synthesis of 5-lipoxygenase products, in particular LTB4, by lung cells after 6 h. There was a positive correlation between the percentage of neutrophils in unfractionated lung cells and the amounts of LTB4 produced by these cells. OA challenge had little or no effect on the production of cLTs and the cyclooxygenase product 12-hydroxy-5,8,10-heptadecatrienoic acid. There was a significant increase in the infiltration of eosinophils into the lungs 24 h after OA challenge but no increase in the production of cLTs by lung cells at this time, suggesting that eosinophils from BN rats are unlikely to be the major site for the production of these substances. This was confirmed in experiments with partially purified eosinophils obtained from Sephadex-treated rats. In contrast, cLTs were major products of arachidonic acid metabolism by alveolar macrophages from BN rats. We conclude that allergen challenge results in an increased capacity of lung cells to synthesize 5-lipoxygenase products, in particular LTB4. Macrophages, rather than eosinophils, may be an important site for the synthesis of cLTs in BN rat lungs.
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PMID:Cellular infiltration and eicosanoid synthesis in brown Norway rat lungs after allergen challenge. 754 78

We determined the effects of selective inhibition of arachidonic acid metabolism via the cyclooxygenase and 5'-lipoxygenase pathways using flurbiprofen and BWA4C, respectively, of 5-hydroxytryptamine (5-HT) using methysergide and of platelet-activating factor (PAF) using WEB 2086 on the airway responses to ovalbumin (OA) aerosol in OA-sensitized Brown Norway rats. Twenty-one days after intraperitoneal injection of OA, rats were exposed to a 1% OA or saline aerosol. Only methysergide (10 mg/kg i.p.; 3 doses over 24 h) provided significant protection of the immediate response to OA. The increase in airway responsiveness to acetylcholine after OA exposure was not significantly altered by methysergide, flurbiprofen (10 mg/kg i.p.), BWA4C (50 mg/kg i.p.) and WEB 2086 (50 mg/kg i.p.) all given over 24 h prior to OA challenge. In addition, there was no effect on the increased recovery of eosinophils and lymphocytes in bronchoalveolar lavage fluid at 24 h. We conclude that 5-HT is an important mediator of the acute response to OA, but that 5-HT, lipoxygenase and cyclooxygenase products and PAF are unlikely to be involved in OA-induced airway hyperresponsiveness and inflammation in the Brown Norway rat.
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PMID:Role of cyclooxygenase and 5-lipoxygenase metabolites, platelet-activating factor and 5-hydroxytryptamine in allergen-induced airway responses in the brown Norway rat. 826 Aug 52

The expression of cyclooxygenase (Cox)-1 and -2 mRNA was studied in tissues of Fisher 344 (F344) (n=3) and Brown Norway (BN) (n=3) strain rats using the reverse transcription polymerase chain reaction. Cox-1 mRNA was expressed in the liver, kidney and lung, but not in the heart. Cox-2 mRNA was expressed in the kidney, heart and lung, but not in the liver. The present results showed the differential expression of basal Cox-1 and Cox-2 mRNA in the rat tissues, suggesting that Cox-1 and Cox-2 may contribute to the regulation of normal pathophysiological conditions in a tissue-specific manner. Thus, it is desirable to perform mapping of the basal expression of Cox-1 and Cox-2 in specific organs in the body in order to anticipate the effects of non-steroidal anti-inflammatory drugs on normal pathophysiological conditions. Finally, no difference was observed between F344 and BN rat tissues in the levels of Cox-1 and Cox-2 mRNA expression.
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PMID:Expression of cyclooxygenase-1 and -2 mRNA in rat tissues: tissue-specific difference in the expression of the basal level of mRNA. 1099 38

Inflammatory pain was induced following an intradermal injection of carrageenin into rat paws, and the hyperalgesia was measured in terms of withdrawal time following thermal pain stimulation of the inflamed paw. This hyperalgesia was significantly less in kininogen-deficient Brown Norway (B/N)-Katholiek rats, which also showed less swelling in carrageenin-induced paw edema, than in normal B/N-Kitasato rats at 1 approximately 4 hr after the carrageenin injection (at the early phase). However, 24 hr after the injection, hyperalgesia and the swelling volume of the kininogen-deficient rats were almost the same as those in normal rats. The bradykinin B2 receptor antagonist FR173657, (E)-3-(6-acetamido-3-pyridyl)-N-[N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl)oxymethyl]phenyl]-N-methylaminocarbonylmethyl]acrylamide, attenuated the carrageenin-induced swelling and hyperalgesia of the normal rats at the early phase to almost the levels of the B/N-Katholiek rats. Pretreatment with indomethacin, a cyclooxygenase inhibitor, also inhibited the carrageenin-induced responses significantly in normal rats. These results indicate that bradykinin, acting on the B2 receptor, is the main mediator at the early phase of inflammatory pain of carrageenin edema and that prostaglandins, produced by cyclooxygenase, potentiate the effects of bradykinin.
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PMID:Evidence for bradykinin mediation of carrageenin-induced inflammatory pain: a study using kininogen-deficient Brown Norway Katholiek rats. 1127 77

The role of small airways in the immediate allergic response is largely unknown. We therefore used the model of precision-cut lung slices (PCLS) in combination with quantitative videomicroscopy to study the early allergic response to allergen in airways ranging from 50 to 900 microm. After PCLS from untreated Wistar rats had been passively sensitized for 16 h with serum from sensitized Brown Norway rats, exposure to 0.1% ovalbumin resulted in an immediate allergic response. Both extent (r = 0.74, p < 0.0001) and velocity (r = 0.49, p < 0.0001) of the allergen-induced bronchoconstriction increased with decreasing airway size. In addition, we observed that smaller airways not only contracted stronger and quicker, but that they also relaxed faster, suggesting that smaller airways are more reactive in principle. The allergen-induced bronchoconstriction in PCLS was prevented by the serotonin receptor antagonist ketanserin (IC(50) 6 nM), but not by antagonists directed against histamine, acetylcholine, PAF, or endothelin receptors, or by cyclooxygenase or lipoxygenase inhibitors. Like allergen, serotonin provoked responses that were stronger in smaller airways. These findings suggest that the immediate allergic response in rat PCLS depends largely on serotonin and that this response can occur in nearly all airway generations, but is most pronounced in the smallest airways, that is, the terminal bronchioles.
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PMID:Immediate allergic response in small airways. 1137 19


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