Cyclopiazonic acid discharges intracellular Ca2+ stores and stimulates Ca2+ influx in cultured human gingival fibroblasts.
The effect of cyclopiazonic acid (CPA) on changes in the intracellular free Ca2+ concentration ([Ca2+]i) evoked by bradykinin (BK), histamine (HIST) and thapsigargin (TG) was investigated in human gingival fibroblasts. CPA itself dose-dependently stimulated [Ca2+]i responses in both the absence and presence of extracellular Ca2+. Pretreatment with CPA (< 5 microM) enhanced the [Ca2+]i responses evoked by 5 nM BK and 1 mM HIST. However, CPA-pretreatment depressed the [Ca2+]i response evoked by 1 microM TG in a dose-dependent manner. Moreover, CPA accelerated the Ca2+ influx caused by 5 nM BK and 1mM HIST, but did not alter that caused by 1 microM TG. These results indicate that CPA discharges intracellular Ca2+ stores, resulting in their depletion, and enhances Ca2+ influx across the plasma membrane.
Matsumoto
Hiroko
H
Department of Pharmacology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
Takeuchi
Reiri
R
Arai
Takafumi
T
Sato
Naoto
N
Akimotot
Yoshiaki
Y
Fujii
Akira
A
D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D019284:Thapsigargin / Q000494:pharmacology
D007211:Indoles; D019284:Thapsigargin; D006632:Histamine; D000252:Calcium-Transporting ATPases; D001920:Bradykinin; D002118:Calcium; C000543:cyclopiazonic acid