Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Although recent observations suggest that endothelin-1 (ET-1) may play a role in the pathogenesis of asthma, to date little is known about the effects of ET-1 on parameters other than bronchoconstriction. The objectives of the present experiments were to study whether intravenously administered ET-1 could exert pro-inflammatory actions in the guinea-pig lung and to assess the involvement of endothelin ETA and ETB receptors in these events by using the ETA receptor-selective antagonist, FR 139317, the novel ETA/ETB receptor antagonist, bosentan and the ETB receptor-selective agonist, IRL 1620. 2. Bolus i.v. injection of ET-1 (0.1-1 nmol kg-1) to anaesthetized guinea-pigs evoked dose-dependent increases in mean arterial blood pressure which lasted for 6-12 min. This was accompanied by a dose-dependent haemoconcentration (8-15% plasma volume losses) and increases (up to 546%) in albumin extravasation in the trachea, upper and lower bronchi, but not in the pulmonary parenchyma. Qualitatively similar changes were observed following i.v. injection of the ETB receptor agonist, IRL 1620 (0.3 and 1 nmol kg-1), although IRL 1620 appeared to be about 3 times less potent than ET-1. The ETA receptor-selective antagonist, FR 139317 (2.5 mg kg-1) inhibited the ET-1 (1 nmol kg-1)-induced pressor response, haemoconcentration and albumin extravasation by 75, 77 and 60-70%, respectively, whereas it did not attenuate IRL 1620 (1 nmol kg-1)-induced changes. The ETA/ETB receptor antagonist, bosentan (10 mg kg-1) almost completely inhibited the pressor, haemoconcentration and permeability effects of both ET-1 and IRL 1620. 3. ET-1, but not IRL 1620 (0.1-1 nmol kg-1), produced a dose-dependent neutropenia with relative lymphocytosis and monocytosis, but did not induce influx of neutrophil granulocytes into pulmonary tissues or the bronchoalveolar space. ET-1 (1 nmol kg-1)-induced neutropenia was prevented by pretreatment of the animals with FR 139317 (2.5 mg kg-1), bosentan (10 mg kg-1) or adrenaline (90 nmol kg-1), indicating that ET-1 caused intravascular sequestration of neutrophil granulocytes. 4. ET-1 or IRL 1620 (10(-10)-10(-6) M) alone did not activate alveolar macrophages in vitro, whereas at a concentration of 10(-8) M, ET-1, but not IRL 1620, markedly potentiated superoxide production in response to f-Met-Leu-Phe (10(-9)-10(-7) M) and platelet-activating factor (PAF, 10(-9)-10(-7) M), but not to phorbol 12-myristate 13-acetate (10(-9) M). ET-1 did not affect f-Met-Leu-Phe- or PAF-induced increases in intracellular free calcium concentration. This potentiating effect of ET-1 was abolished by FR 139317(1.5 X 10-7 M).5. We conclude that, in addition to evoking airway contractions, ET-1 exerts pro-inflammatory actions via activation of the ETA and to a lesser extent the ETB receptors, and therefore, might contribute to the airway inflammation present in asthma. These findings also suggest the therapeutic potential of ETA/ETB receptor and perhaps ETA receptor-selective antagonists in this disease.
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PMID:Acute pro-inflammatory actions of endothelin-1 in the guinea-pig lung: involvement of ETA and ETB receptors. 767 Jul 25

The influence of pentoxifylline (PTX) on mortality and some important mediators was studied in a model of cecal perforation with fulminant intra-abdominal sepsis in rats. Cumulative mortality was registered in three groups of animals: untreated sepsis (n = 36), sepsis + PTX 20 mg/kg/24 h (n = 24), and sepsis + PTX 80 mg/kg/24 h (n = 24). PTX therapy was started at sepsis induction or after 4 h, and mortality was reduced from 89% in untreated sepsis to 60-66% in the PTX groups. Levels of sepsis mediators were studied in two groups: untreated sepsis and sepsis + PTX 40 mg/kg started 1 h after sepsis induction. In both groups 6-10 animals were sacrificed at 4 and 8 h to measure blood levels of bacteria, endotoxin, tumor necrosis factor (TNF), interleukin-6 (IL-6), endothelin-1, lactate, neutrophils, and packed cell volume. Cecal perforation gave high levels of bacteria, endotoxin, TNF, IL-6, and endothelin-1, leading to dehydration, lactacidosis, neutropenia, and death. Treatment with PTX did not modify dehydration, neutropenia, or concentrations of bacteria and endotoxin. Release of endothelin-1 was delayed, TNF burst was nearly abolished, and levels of IL-6 and lactate were substantially suppressed. In summary, PTX improves survival and reduces blood concentrations of TNF, IL-6, lactate, and endothelin-1 in fulminant intra-abdominal sepsis in rats. The primary effect of PTX in this sequence is probably reduction of TNF.
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PMID:Pentoxifylline improves survival and reduces tumor necrosis factor, interleukin-6, and endothelin-1 in fulminant intra-abdominal sepsis in rats. 777 1