Aluminofluoride activates hyperpolarization- and stretch-activated cationic channels in single smooth muscle cells.
Aluminofluoride (AF) has a variety of biological actions such as activation of GTP binding proteins and inhibition of phosphatases. In the present study, the effects of AF on hyper-polarization- and stretch-activated cationic channels (HA-SACs) were investigated in isolated gastric smooth muscle cells from the toad, Bufo marinus, using the patch-clamp technique. In cell-attached patches extracellular application of AF (20 mM KF plus 20 microM AlCl3) reversibly increased HA-SAC activity without changing its voltage sensitivity. The single channel current amplitude of HA-SACs was not affected during this procedure. The mechanism of AF-induced activation of HA-SACs remains unclear. However, this activation may play a role in contraction of smooth muscle induced by AF.
Hisada
T
T
Department of Physiology, University of Massachusetts Medical Center, Worcester 01655.
Singer
J J
JJ
Walsh
J V
JV
D000535:Aluminum / Q000494:pharmacology*; D017607:Aluminum Compounds; D000818:Animals; D002024:Bufo marinus; D005459:Fluorides / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects* / Q000502:physiology; D008564:Membrane Potentials; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013270:Stomach / Q000166:cytology
D017607:Aluminum Compounds; D007473:Ion Channels; D000535:Aluminum; D005459:Fluorides; C032311:aluminum fluoride