The caffeine evoked effects on the intracellular Ca2+ concentration ([Ca2+]i) and on the release of dopamine by PC12 cells were investigated. Stimulation by caffeine resulted in a transient Ca2+ release which was followed by a sustained phase of Ca2+ entry through a non-voltage dependent pathway. Treatment with cyclopiazonic acid (CPA) or thapsigargin, inhibitors of the Ca2+ ATPase pump of the endoplasmic reticulum, resulted in only a sustained rise in [Ca2+]i in the presence of extracellular Ca2+. Pretreatment of cells with CPA or thapsigargin abolished the subsequent Ca2+ responses to caffeine. Caffeine also evoked the release of dopamine from the cells only in the presence of extracellular Ca2+, which was mimicked by CPA. These results suggest that store-dependent Ca2+ entry evoked by caffeine has an indispensable role in the secretory response in an excitable cell line, PC12 cells.
|Number of pages||5|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Mar 6 1998|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology