Effects of TMB-8, a calcium antagonist, on transport properties of the isolated canine tracheal epithelium.
The effects of the putative intracellular Ca2+ antagonist, TMB-8 (8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate), on the canine tracheal epithelium were examined. Luminal addition reduced rapidly, but reversibly, the transmucosal potential difference and increased the resistance across the open-circuited epithelium. Under short-circuit conditions, the drug reduced stimulation by prostaglandin E2, forskolin, 8-bromo cyclic AMP, prostaglandin F2 alpha and A23187. Inhibition of prostaglandin E2 responses were accompanied by reversal of net Cl- fluxes produced by the agonist. The effects of TMB-8 were unaffected by increasing Ca2+ in the bathing solutions, and were not mimicked by procaine, nitrendipine, calmidazolium, compound 48/80 or trifluoperazine. W7 did, to a limited extent, produce similar responses, though the drug was more toxic, and the effects were irreversible.
D015056:1-Methyl-3-isobutylxanthine / Q000037:antagonists & inhibitors; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000037:antagonists & inhibitors; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D000001:Calcimycin / Q000037:antagonists & inhibitors; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002712:Chlorides / Q000378:metabolism*; D005576:Colforsin / Q000037:antagonists & inhibitors; D015237:Dinoprost; D015232:Dinoprostone; D004285:Dogs; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology; D011458:Prostaglandins E / Q000037:antagonists & inhibitors; D011460:Prostaglandins F / Q000037:antagonists & inhibitors; D012964:Sodium / Q000378:metabolism*; D014132:Trachea / Q000187:drug effects* / Q000378:metabolism
D002121:Calcium Channel Blockers; D002147:Calmodulin; D002712:Chlorides; D011458:Prostaglandins E; D011460:Prostaglandins F; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000001:Calcimycin; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D012964:Sodium; D015237:Dinoprost; D015232:Dinoprostone; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine; D010634:Phenobarbital