Possible involvement of arachidonic acid and eicosanoids in metamorphic events in Hydractinia echinata (Coelenterata; Hydrozoa).
Upon induction of metamorphosis, larvae of the marine hydroid Hydractinia echinata release [14C]-arachidonic acid from previously labeled endogenous sources. The lipoxygenase inhibitors nordihydroguaiaretic acid and 5,8,11,14-eicosatetraynoic acid inhibited metamorphosis induced by Cs+ and 1,2-sn-dioctanoylglycerol, whereas the inhibitors of cyclooxygenase, indomethacin, and acetylsalicylic acid were ineffective, suggesting a role for lipoxygenase metabolites of arachidonic acid in induction of metamorphosis. Lipoxygenase products in Hydractinia echinata were isolated and identified by gas chromatography/mass spectrometry. 8- and 12-HETE were the most abundant metabolites. In cytosolic fractions from larvae activity of an arachidonic acid metabolizing enzyme, presumably a lipoxygenase, was found. The metabolic product was identified by 1H-NMR and chiral phase HPLC as 8(R)-HETE. Its production was strongly inhibited by NDGA, but not by indomethacin.
Leitz
T
T
Zoologisches Institut der Universität, Heidelberg, Germany.
Beck
H
H
Stephan
M
M
Lehmann
W D
WD
De Petrocellis
L
L
Di Marzo
V
V
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001241:Aspirin / Q000494:pharmacology; D002250:Carbon Radioisotopes; D015777:Eicosanoids / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006829:Hydra / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006893:Hydroxyeicosatetraenoic Acids / Q000032:analysis / Q000378:metabolism; D007213:Indomethacin / Q000494:pharmacology; D008084:Lipoxygenase / Q000378:metabolism; D009637:Masoprocol / Q000494:pharmacology; D008675:Metamorphosis, Biological / Q000187:drug effects / Q000502:physiology*; D010743:Phospholipids / Q000378:metabolism
D002250:Carbon Radioisotopes; D015777:Eicosanoids; D006893:Hydroxyeicosatetraenoic Acids; D010743:Phospholipids; D015117:5,8,11,14-Eicosatetraynoic Acid; D016718:Arachidonic Acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C047628:8-hydroxyeicosatetraenoic acid; D009637:Masoprocol; D008084:Lipoxygenase; D001241:Aspirin; D007213:Indomethacin