These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Membrane stretch: a physiological stimulator of Ca2+-activated K+ channels in thick ascending limb.
    Author: Taniguchi J, Guggino WB.
    Journal: Am J Physiol; 1989 Sep; 257(3 Pt 2):F347-52. PubMed ID: 2782419.
    Abstract:
    The effects of membrane stretch on Ca2+-activated (maxi) K+ channels were examined in the apical membrane of cultured medullary thick ascending limb (MTAL) cells. Using cell-attached patchclamp technique, we found that negative pressure (-33 +/- 5 cmH2O) applied to the patch membrane increased fractional open probability (NPo) from 0.3 +/- 0.2 to 29.9 +/- 7.6% (n = 12) in the presence of 1.8 mM Ca2+ in the pipette. The activity returned to control on releasing the negative pressure. Reduction of extracellular osmolality from 293.2 +/- 1.6 to 219.8 +/- 1.1 mosmol/kg also activated K+ channels (NPo = 43.8 +/- 12.2%, n = 8) in cell-attached patches. Removal of Ca2+ from both pipette and bathing solution inhibited osmotic activation of K+ channels. K+ channels were shown to be Ca2+-activated K+ channels by their conductance (146 +/- 7 pS, n = 5) and Ca2+ dependence. Our data suggest that membrane stretch caused by swelling or possibly by tubular flow enhances Ca2+ entry across the apical cell membrane of MTAL cells activating maxi K+ channels.
    [Abstract] [Full Text] [Related] [New Search]