Abstract
Using the whole-cell and single channel recording techniques, the influence of actin cytoskeletons on L-type Ca2+ current was investigated in human gastric smooth muscle cells. In isotonic condition, an actin depolymerizer cytochalasin D (Cyt-D) markedly decreased the whole-cell current (IBa) without changing steady-state voltage dependency and single channel conductance. Intracellular dialysis of phalloidin, an actin polymerizer, significantly increased the IBa. Hypotonic stretch (222 mOsm/L) of the myocytes increased the IBa, and Cyt-D significantly inhibited the IBa increase by the stretch. Phalloidin was without effect on the IBa increase by the stretch. Phalloidin antagonized the Cyt-D inhibition of the stretch-induced IBa increase. Neither heterotrimeric G protein modifiers (GTPγS and GDPβS) nor rho GTPase inhibitor (C3 exoenzyme) influenced the stretch-induced responses. These results reveal that the integrity of the actin cytoskeleton is an important factor which determines the activity of L-type Ca2+ channels and a response to stretch.
Original language | English (US) |
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Pages (from-to) | 503-508 |
Number of pages | 6 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 352 |
Issue number | 2 |
DOIs | |
State | Published - Jan 12 2007 |
Externally published | Yes |
Keywords
- Actin cytoskeletons
- Cytochalasin D
- Human stomach
- L-type Ca channels
- Phalloidin
- Smooth muscle
- Stretch
- Swelling
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology