Opening of Ca(2+)-dependent K+ channels by nordihydroguaiaretic acid in porcine coronary arterial smooth muscle cells.
Effects of nordihydroguaiaretic acid (NDGA) on the Ca(2+)-dependent K+ channel (BK channel) were examined by the patch clamp technique in single smooth muscle cells of porcine coronary artery. The open probability of BK channels in inside-out patches increased by about 30 times at the holding potential of 0 mV, when 10 microM NDGA was added to the bathing solution (pCa 7.0). The effect of NDGA was concentration-dependent in the range of 1-100 microM and partly removed by washout. The enhancement of BK channels by NDGA was not observed when the cytosolic Ca2+ concentration was very low (pCa > 8.5). These results clearly indicate that NDGA possesses a BK channel opening property in coronary arterial myocytes.
Nagano
N
N
Department of Chemical Pharmacology, Nagoya City University, Japan.
Imaizumi
Y
Y
Hirano
M
M
Watanabe
M
M
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D009637:Masoprocol / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000819:agonists*; D013552:Swine; D014665:Vasodilator Agents / Q000494:pharmacology
D015221:Potassium Channels; D014665:Vasodilator Agents; D009637:Masoprocol