Effects of tetrabutylhydroperoxide on hepatocyte ion channels.
As shown previously, tetrabutylhydroperoxide (t-BOOH) shrinks hepatocytes by release of cellular K(+). The hyperpolarization, the increase of K(+) selectivity, and the Ba(2+) sensitivity of K(+) release have been taken as evidence of activation of K(+) channels. To further define the ion channels involved, patch-clamp studies have been performed on rat hepatocytes. The data show that 0.1 mmol/l t-BOOH inhibits an inwardly rectifying K(+) channel and simultaneously activates a 35-pS K(+) channel. It is suggested that the activation of the latter channel population contributes to the observed K(+) release of hepatocytes following exposure to t-BOOH.
Breit
S
S
Physiologisches Institut der Universität Tübingen, Deutschland.
Kolb
H A
HA
Häussinger
D
D
Lang
F
F
D000818:Animals; D002478:Cells, Cultured; D008099:Liver / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying; D051381:Rats; D020122:tert-Butylhydroperoxide / Q000494:pharmacology*
D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D020122:tert-Butylhydroperoxide; D011188:Potassium