Arachidonic acid increases cholinergic secretory responsiveness of ferret tracheal glands.
The purpose of this study was to determine if arachidonic acid could alter ferret tracheal gland secretory responsiveness to a cholinergic agonist. We prepared glandular explants and incubated the explants in medium containing [3H]glucosamine. Secretory responsiveness was expressed as the percent change in basal secretion of acid-precipitable [3H]glucosamine-labeled glycoconjugates induced by the addition of agonist with and without arachidonic acid [mean +/- SE (n)]. Addition of 10(-3) M arachidonic acid caused a significant increase in secretion [28 +/- 6% (n = 6)] compared with untreated control tissues [-10 +/- 4% (n = 7), P less than or equal to 0.05]. Carbachol (10(-7) M) increased secretion 39 +/- 9% (n = 7). The combination of 10(-3) M arachidonic acid and 10(-7) M carbachol elicited a significantly greater change in secretion compared with either agent alone [173 +/- 50% (n = 5)]. The addition of nordihydroguaiaretic acid (10(-6) M) or indomethacin (10(-6) M) partially attenuated the arachidonic acid-enhanced secretory responsiveness to carbachol. Treatment with both blockers completely inhibited the arachidonic acid-enhanced secretory responsiveness to carbachol. The effect of arachidonic acid on cholinergic stimulation was also abolished by treating the explant cultures with tetrodotoxin (10(-7) M). This hypersecretory state is most likely mediated by eicosanoid-induced release of neurotransmitters from nerve terminals.
McBride
R K
RK
Department of Medicine, University of Rochester, School of Medicine and Dentistry, New York 14642-8692.
Stone
K K
KK
Marin
M G
MG
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D002217:Carbachol / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005289:Ferrets; D005944:Glucosamine / Q000378:metabolism*; D006001:Glycoconjugates / Q000378:metabolism*; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D008042:Linolenic Acids / Q000494:pharmacology*; D009637:Masoprocol / Q000494:pharmacology; D009092:Mucous Membrane / Q000187:drug effects / Q000502:physiology; D014132:Trachea / Q000187:drug effects / Q000502:physiology*; D014316:Tritium
D006001:Glycoconjugates; D008042:Linolenic Acids; D014316:Tritium; D016718:Arachidonic Acid; D009637:Masoprocol; D002217:Carbachol; D005944:Glucosamine; D007213:Indomethacin