Deutsches Krebsforschungszentrum 
German Cancer Resarch CenterLOX-DB - LipOXygenases DataBase
Lipoxygenases...
What are Lipoxygenases?
Lipoxygenases and
cancer research
Database...
Search
Display all entries
Alignments
Sequence Comparison
Blast Search
Search Literature
Search Literature (adv.)
Misc...
Image Gallery
Links
Forum
Contact
Guestbook
Home

LOX-DB - Literature


The role of cyclooxygenase and 5-lipoxygenase metabolites in potentiated endothelin-1-evoked contractions in bovine bronchi.

Nally J.E., Bunton D.C., Martin D., Thomson N.C.

Pulm. Pharmacol. 9: 211-217 (1996)

Abstract:

We have previously shown that angiotensin II (AII) potentiates responses evoked by endothelin-1 (Et-1). In the present study, the additional ability of hypoxia or phorbol 12, 13-dibutyrate (PDBu) to evoke hyperreactivity was examined. In addition, the role of cyclooxygenase and 5-lipoxygenase metabolites of arachidonic acid in the potentiation evoked by AII, hypoxia or PDBu was studied, using indomethacin and nordihydroguaiaretic acid (NDGA). The involvement of protein kinase C in the enhanced response was examined using staurosporine. Contractions were measured isometrically from rings of bovine bronchi. Contractions evoked by Et-1 alone were unaltered by indomethacin (10(-6)M), NDGA (10(-5)M) or staurosporine (3 x 10(-8)M). AII (3 x 10(-7)M), hypoxia (4% O2) or PDBu (10(-8)M) each significantly potentiated the contractions evoked by Et-1. Indomethacin (10(-6)M) virtually abolished the effect of AII, hypoxia or PDBu. NDGA (10(-5)M) reversed the potentiating effect of both AII and hypoxia and partially reversed PDBu-evoked enhancement of Et-1-mediated responses. Staurosporine (3 x 10(-8)M) abolished the ability of AII or PDBu, but not hypoxia, to enhance Et-1-mediated contractions. In conclusion, AII, hypoxia and PDBu evoke hyperresponsiveness which is mediated by prostanoids and/or leukotrienes, the precise nature of which remains to be elucidated. Differences in the ability of staurosporine to reverse AII- and hypoxia-induced hyperreactivity suggests, however, that these conditions may generate different eicosanoids.

LOX-DB entries related to this article: bt-5-lox