FCCP modulation of Ca2+ oscillation in rat megakaryocytes.
The effects of a mitochondrial uncoupler, FCCP, (carbonyl cyanide-p-trifluromethoxyphenyl-hydrazone) on the regulation of cytoplasmic Ca2+ were investigated in ATP-induced Ca2+ oscillation system of rat megakaryocyte. Application of FCCP did not induce any detectable Ca(2+)-activated K+ current (IKCa) but pretreatment with FCCP modulated the ATP-induced repetitive IKCa. FCCP abolished the IKCa induced by low concentrations of ATP. However, when the concentration of ATP was high, the uncoupler also changed the periodic current to a sustained one. Similar biphasic regulation by the uncoupler was observed in the case of IP3-evoked repetitive IKCa. These results indicate that FCCP inhibits both Ca2+ mobilization and elimination processes after IP3 liberation induced by agonist stimulation.
Uneyama
C
C
Division of Pathology, National Institute of Health Sciences, Tokyo, Japan.
Uneyama
H
H
Takahashi
M
M
Akaike
N
N
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism; D001854:Bone Marrow Cells; D002118:Calcium / Q000378:metabolism*; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology*; D004594:Electrophysiology; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008297:Male; D008533:Megakaryocytes / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D014475:Uncoupling Agents / Q000494:pharmacology*
D014475:Uncoupling Agents; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate; D002118:Calcium