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Possible role of leukotrienes in hypoxic contraction of canine isolated basilar artery
Author(s) -
Gu Mai,
Elliott Douglas A.,
Ong Bill Y.,
Bose Deepak
Publication year - 1991
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1991.tb09839.x
Subject(s) - basilar artery , contraction (grammar) , arachidonic acid , hypoxia (environmental) , phospholipase a2 , endocrinology , leukotriene , isometric exercise , medicine , antagonist , chemistry , muscle contraction , biochemistry , enzyme , receptor , oxygen , organic chemistry , asthma
1 Hypoxia reversibly increased isometric tension in unstimulated canine isolated basilar artery rings. 2 Nordihydroguäiaretic acid (NDGA; 5 × 10 −6 m ), an inhibitor of lipoxygenase and quinacrine (10 −5 m ), which blocks the release of arachidonic acid from phospholipids by inhibiting the enzyme phospholipase A 2 , blocked hypoxia‐induced contractions. 3 The preferential leukotriene D 4 (LTD 4 ) antagonist, L‐660,711, also inhibited the hypoxia‐induced contractions in concentrations ranging from 10 −8 m to 10 −5 m . The effects seen were statistically significant ( P < 0.05). Two components of inhibition were seen. 4 Arachidonic acid (5 μg ml −1 ) caused contraction of the isolated basilar artery rings. This response was inhibited by NDGA (5 × 10 −6 m ) and L‐660,711 (10 −5 m ). 5 The LTD 4 (10 −8 m –10 −7 m )‐induced contraction was relaxed by L‐660,711 in a dose‐dependent manner. Both the contraction caused by LTD 4 as well as that caused by hypoxia were relaxed by 5 × 10 −6 m adenosine. 6 Leukotriene(s) may be involved in hypoxia‐induced contraction of canine isolated basilar artery. However, they may not be the sole mediator(s).