Ryanodine-induced intracellular calcium mobilisation in cultured astrocytes.
Changes in intracellular Ca2+ concentration were monitored in cultured cortical astrocytes challenged with ryanodine and ATP. Ryanodine elicited a modest, in comparison to ATP, increase in cytosolic Ca2+ concentration in approximately 60% of the cell fields examined. This effect was evident and, in fact, was augmented when incubations were performed in Ca(2+)-free bathing medium. In addition, ryanodine-evoked changes in intracellular Ca2+ concentration were dose dependent, desensitised rapidly, and could not be mimicked by caffeine. Exposure to ryanodine was without effect on eicosanoid release from these cells nor did it influence Ca2+ mobilisation and eicosanoid release in response to ATP. In contrast, caffeine attenuated part of the ATP-evoked increase in intracellular Ca2+ concentration in the majority of cells tested and abolished its effect on eicosanoid release.
Langley
D
D
Department of Pharmacology, School of Pharmacy, London, United Kingdom.
Pearce
B
B
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007700:Kinetics; D051381:Rats; D012433:Ryanodine / Q000494:pharmacology*; D013928:Thromboxane A2 / Q000378:metabolism
D012433:Ryanodine; D002110:Caffeine; D013928:Thromboxane A2; D000255:Adenosine Triphosphate; D002118:Calcium