Cysteinyl leukotrienes, synthesized de novo from cell membrane phospholipids, are proinflammatory mediators that play an important role in the pathophysiology of asthma. These mediators are among the most potent of bronchoconstrictors and cause vasodilation, increased microvascular permeability, exudation of macromolecules and edema. The cysteinyl leukotrienes also have potent chemoattractant p...

The ability of leukotrienes derived from eicosapentaenoic acid were compared with counterpart leukotrienes derived from arachidonic acid in terms of their ability to affect susceptibility of the stomach to injury induced by a topical irritant and their ability to alter gastric blood flow. Intra-arterial infusion of leukotriene C4 (LTC4) and LTD4 (0.1-3 micrograms/kg/min for 5 min) produced dose...

Systemic sclerosis (SSc, scleroderma) is an autoimmune disease characterized by widespread vascular injury and progressive fibrosis of the skin and internal organs. SSc-related involvement of the lungs, heart, kidneys and/or the gastrointestinal system accounts for the increased mortality of scleroderma patients. Despite the progress which has recently been made in this field, the treatment of ...

Asthma is a complex syndrome characterized by variable obstruction to airflow, bronchial hyperresponsiveness, and inflammation. The initiation and propagation of airway inflammation arises from many factors, including mediators generated by resident airway cells and recruited leukocytes (1). Leukotrienes are biologically active fatty acids derived from the oxidative metabolism of arachidonic ac...

The liver is the major organ which eliminates leukotriene C4 (LTC4) and other cysteinyl leukotrienes from the blood circulation into bile. Transport of LTC4 was studied using inside-out vesicles enriched in canalicular and sinusoidal membranes from rat liver. The incubation of canalicular membrane vesicles with [3H]LTC4 in the presence of ATP resulted in an uptake of LTC4 into vesicles. The ini...

The hematopoietic cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) is being used in clinical trials for its potential in the treatment of hematopoietic insufficiency due to various causes. Involvement of leukotrienes in the effects of GM-CSF is suggested by analytical and pharmacologic evidence obtained in vitro. However, until now no data in support of a role of leukotrienes ...

BACKGROUND Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs) and thromboxane A2 (TXA2). The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. METHODS A trimellitic anhydri...

BACKGROUND We have previously reported that asthma differs from rhinitis with or without bronchial hyperresponsiveness in the perception and degree of lower airway inflammation. OBJECTIVE The aim of the present study was to investigate whether sputum levels of inflammatory markers could further distinguish these patient groups. METHODS Patients with seasonal allergic rhinitis with or withou...

The slow-reacting substances (SRS) consist of leukotrienes C, D, and E (LTC, -D, -E) 1 and are derived from the lipoxygenase pathway of arachidonic acid (20:4) metabolism. In examining possible mechanisms for the vasoactive effects of SRS (1-4), we found that cultures o f human endothelial cells release the vasodilatory agent, prostacyclin, on exposure to 10 -9 to 10 -6 M LTC (5). Previous repo...