Allergic reactions, leukotriene

Triggering of asthma attacks in asthmatics. This side effect is a pseudo-allergic reaction where COX-inhibition increases the availability of substrates for lipoxygenase, which are converted to broncho-constrictive leukotriens... 

Leukotrienes increase capillary permeability and serve as chemotactic factors for neutrophil granulocytes. As "slow-reacting substances of anaphylaxis," they are involved in allergic reactions (p. 326) together with PG, they evoke the spectrum of characteristic inflammatory symptoms redness, heat, swelling, and pain. 

IgE-mediated allergic reactions (p. 72) involve mast cell release of histamine (p. 114) and production of other mediators (such as leukotrienes, p. 196). Resultant responses include relaxation of vascular smooth muscle, as evidenced locally by vasodilation (e.g., conjunctival congestion) or systemically by hypotension (as in anaphylactic shock) enhanced capillary permeability with transudation of fluid into tissues— swelling of conjunctiva and mucous membranes of the upper airways ( hay fever ), cutaneous wheal formation contraction of bronchial smooth muscle-bronchial asthma stimulation of intestinal smooth musde—diarrhea. 

Sinus problems, hay fever, bronchial asthma, hives, eczema, contact dermatitis, food allergies, and reactions to drugs are all allergic reactions associated with the release of histamine and other autocoids, such as serotonin, leukotrienes, and prostaglandins. Histamine release is frequently associated with various inflammatory states and may be increased in urticarial reactions, mastocytosis, and basophilia. Histamine also acts as a neurotransmitter in the central nervous system (CNS). Upon release from its storage sites, histamine exerts effects ranging from mild irritation and itching to anaphylactic shock and eventual death. 

As the research area expanded, the leukotrienes were discovered next. The leukotrienes are potent lipid mediators associated with asthma and allergic reactions. In contrast to prostaglandins, leukotrienes are made predominantly in inflammatory cells, like leukocytes, macrophages, and mast cells. 

Total maximum score was ll.17 Nasal lavage samples were also taken before and immediately after the nasal allergen challenge and analyzed for the allergic reaction and inflammatory mediators PGD2 leukotrienes C, T, and E4 and tryptase. 

The peptide leukotrienes 99,100, and 101 cause contraction of the bronchial smooth muscle and probably play an important role as mediators in allergic reactions (e.g. asthma) and inflammations. Antagonistic blockade of the leukotriene action of 99,100, and 101, by analogy with histamine Hj-reccptor antagonists, would therefore be an important principle in the treatment of allergic symptoms. A number of selective peptide leukotriene antagonists have in fact been synthesized by Smith Kline ... 

Arachidonic acid can also be converted into a leukotriene. Because they induce contraction of the muscle that lines the airways to the lungs, leukotrienes are implicated in allergic reactions, inflammatory reactions, and heart attacks. Leukotrienes also bring on the symptoms of asthma and are implicated in anaphylactic shock, a potentially fatal allergic reaction. There are several antileukotriene agents available for the treatment of asthma. 

Samuelsson B (1981) Leukotrienes Mediators of allergic reactions and inflammation. Int Arch Allergy Appl Immunol [Suppl 1] 66 98... 

Leukotrienes A family of molecules that are synthesized from arachidonic acid by the lipoxygenase pathway and function as local hormones, primarily to promote inflammatory and allergic reactions (such as the bronchial construction of asthma). 

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