Effects of 5-oxo-ETE and 14,15-EET on reactivity and Ca2+ sensitivity in guinea pig bronchi.
The reactivity and Ca2+ sensitivity of fresh as well as organ-cultured guinea pig bronchi challenged with 5-oxo-ETE and 14,15-EET were compared. Tension measurements, performed on fresh and 3-day cultured bronchi, revealed that the contractile responses to 5-oxo-ETE were largely increased in cultured explants, while 14,15-EET induced larger relaxations on Carbamylcholine (CCh) pre-contracted explants. In fresh bronchi, the contractile responses to 5-oxo-ETE were inhibited by 10 microM indomethacin whereas the relaxing responses induced by 14,15-EET were amplified in the presence of COX inhibitors. COX down expression resulted in a lack of indomethacin effect in cultured explants. One micromolar 5-oxo-ETE increased Ca2+ sensitivity in beta-escin-permeabilized cultured explants, while 1 microM Y-27632 abolished this hypersensitivity. In contrast, 1 microM 14,15-EET significantly reduced the Ca2+ hypersensitivity developed by cultured bronchi. In conclusion, pre-treatment of cultured guinea pig bronchi for 48 h with these eicosanoids modifies the pharmacological responsiveness and Ca2+ sensitivity of these cultured explants.
Morin
Caroline
C
Le Bilarium, Department of Physiology and Biophysics, Faculty of Medicine and Health Sciences, University of Sherbrooke 3001, 12th avenue north, Sherbrooke, J1H 5N4, Que., Canada.
Rousseau
Eric
E
D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D008297:Male; D009924:Organ Culture Techniques
D001095:Arachidonic Acids; D016861:Cyclooxygenase Inhibitors; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid; D015126:8,11,14-Eicosatrienoic Acid; D002118:Calcium