title: Novel hypothalamic arachidonate products stimulate somatostatin release from the median eminence.
abstract: Arachidonic acid (AA) stimulates the in vitro release of somatostatin (SRIF) from the hypothalamic median eminence (ME). This effect is inhibited by 5, 8, 11, 14-eicosatetraynoic acid (ETYA) but not by indomethacin (ID). Microsomal fractions from the rat hypothalamus catalyze an NADPH-dependent metabolism of AA to form several oxygenated products of which the major metabolites are 5, 6-epoxyeicosatrienoic acid (5, 6-EET) and its hydration product, 5, 6-dihydroxyeicosatrienoic acid (5, 6-DHET). Both novel arachidonate metabolites, particularly 5, 6-EET, are potent in vitro stimuli for the release of SRIF. To a lesser extent, 5, 6-EET is also capable of evoking luteinizing hormone-releasing hormone (LHRH) release. The results suggest that these "epoxygenase" metabolites of AA may be physiologically involved in the control of SRIF release.
mesh_terms: D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008473:Median Eminence / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013004:Somatostatin / Q000378:metabolism*
chemical_list: D001095:Arachidonic Acids; D015117:5,8,11,14-Eicosatetraynoic Acid; D016718:Arachidonic Acid; D013004:Somatostatin; D007213:Indomethacin