Interaction between the intracellular Ca2+ stores in rat dissociated hippocampal neurones.
The interaction between the Ca(2+)-activated K+ currents (IK(Ca)) induced by acetylcholine (ACh), 1-aminocyclopentane-1S,3R-dicarboxylic acid (1S,3R)-ACPD) and caffeine in rat hippocampal CA1 neurones was investigated to examine the functional independence between IP3- and Ca(2+)-sensitive Ca2+ stores. Pretreatment with either ACh or (1S,3R)-ACPD almost completely suppressed the subsequent IK(Ca) induced by another. Pretreatment with caffeine partially suppressed the IK(Ca) induced by either ACh or (1S,3R)-ACPD, although the inhibitory effect varied among the neurones, while pretreatment with either ACh or (1S,3R)-ACPD also partially inhibited the caffeine-induced IK(Ca). Continuous treatment with ryanodine and thapsigargin nonselectively decreased both the caffeine- and ACh-induced IK(Ca). These results thus indicate a close interaction between IP3- and Ca(2+)-sensitive stores and also suggest that the relative size of both stores and the closeness between them differ among neurones.
Imanishi
T
T
Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Yamanaka
H
H
Rhee
J S
JS
Akaike
N
N
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D018679:Cholinergic Agonists / Q000494:pharmacology*; D003515:Cycloleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects; D051381:Rats
D018679:Cholinergic Agonists; D015221:Potassium Channels; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D002110:Caffeine; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium