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Bovine polymorphonuclear leukocytes increase sensitivity to noradrenaline in isolated mesenteric arteries
Author(s) -
Kimpe S.J.,
HeuvenNolsen D.,
Nijkamp F.P.
Publication year - 1992
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.1476-5381.1992.tb09022.x
Subject(s) - prostacyclin , mesenteric arteries , nordihydroguaiaretic acid , contraction (grammar) , superoxide dismutase , medicine , superoxide , chemistry , endocrinology , endothelium , vascular smooth muscle , prostaglandin , pyrogallol , biochemistry , artery , biology , cyclooxygenase , enzyme , smooth muscle
1 The effects of polymorphonuclear leukocytes (PMN) on vascular function to (−)‐noradrenaline were examined in vitro. Purified bovine PMN were incubated in siliconized organ baths containing rings of bovine mesenteric arteries, after which a concentration‐effect curve in response to (−)‐noradrenaline was obtained. 2 PMN‐derived products induced a long lasting concentration‐dependent contraction of the blood vessels generating 24.4 ± 6.8% of the maximal tension to (−)‐noradrenaline at a cell concentration of 2.5 × 10 6 ml −1 . The contractile response was also found in endothelium‐denuded vascular rings. 3 PMN present in the organ bath caused an increase in the sensitivity of vascular rings to (−)‐noradrenaline. At a cell number of 2.5 × 10 6 PMN ml −1 the pD 2 ‐value for (−)‐noradrenaline was augmented 0.40 ± 0.05 ( P < 0.001), while total contraction at the highest concentration (−)‐noradrenaline was not affected. This increase in sensitivity was dependent on an intact endothelium. 4 The increase in sensitivity to (−)‐noradrenaline by PMN was inhibited by superoxide dismutase, but not by catalase, dimethylthiourea, indomethacin or nordihydroguaiaretic acid. The non‐stimulated bovine PMN produced oxygen radicals as measured by chemiluminescence. 5 Simultaneous incubation of PMN and (−)‐noradrenaline with arterial rings induced an increase in the release of prostacyclin, measured by an elevated concentration of 6‐keto‐prostaglandin F α in the supernatant. 6 It is concluded that PMN can increase vascular tone directly or indirectly probably via the interaction of PMN‐derived superoxide anions with endothelium‐derived relaxing factor.