Cytochrome P450 inhibitors attenuate the hypotonic shock-induced increases in K+ efflux in LLC-PK1 cells.
Cell volume regulation in LLC-PK1 cells was evaluated by measuring 86Rb efflux (rate constant), used as an indicator of K+ efflux. Hypotonic shock induced a transient increase in the rate constant which returned to baseline values after 15 min. ETYA, an arachidonic acid-competitive antagonist as well as the cytochrome P450 inhibitors SKF 525-A, clotrimazole and 7-ethoxyresorufin, inhibited the hypotonic shock-induced increment in the rate constant. Arachidonic acid did not change hypotonic shock-induced increments in K+ efflux. LLC-PK1 cells were unable to metabolize 14C-arachidonic acid. We concluded that although arachidonic acid inhibitors block the hypotonic shock-induced increment in K+ efflux, this effect cannot be related to inhibition of arachidonic acid metabolism.
DelliPizzi
A M
AM
Department of Pharmacology, New York Medical College, Valhalla, NY, USA.
McGiff
J C
JC
Escalante
B
B
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D018374:LLC-PK1 Cells / Q000187:drug effects*; D009997:Osmotic Pressure; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism; D013552:Swine
D016718:Arachidonic Acid; D003577:Cytochrome P-450 Enzyme System; D012413:Rubidium; D011188:Potassium