Effect of high hydrostatic pressure on the BK channel in bovine chromaffin cells.
The activity of the BK channel of bovine chromaffin cells was studied at high hydrostatic pressure, using inside-out patches in symmetrical KCl solution, Ca2+-free and at V(H) = -60 to -40 mV. Pressure increased the probability of channels being open (900 atm increasing the probability 30-fold), and it increased the minimum number of channels apparent in the patches. The pressure activation of the channel was reversed on decompression. Channel conductance was unaffected. It was shown that pressure did not act by raising the temperature, or by affecting [Ca] or pH, or the order of the membrane bilayer, and it was concluded that pressure most likely acted directly on the channel proteins and/or their modulating reactions.
Macdonald
A G
AG
Department of Biomedical Sciences, University of Aberdeen, Scotland, UK. a.macdonald@abdn.ac.uk
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002417:Cattle; D019439:Chromaffin Cells / Q000378:metabolism*; D004553:Electric Conductivity; D006874:Hydrostatic Pressure; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008564:Membrane Potentials; D018408:Patch-Clamp Techniques / Q000295:instrumentation; D015221:Potassium Channels / Q000737:chemistry / Q000378:metabolism*; D024681:Potassium Channels, Calcium-Activated
D051036:Large-Conductance Calcium-Activated Potassium Channels; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated