title: Effects of caffeine on phosphatidylinositide turnover and calcium mobilization in human neuroblastoma SK-N-SH cells.
abstract: The effects of caffeine on receptor-controlled Ca2+ mobilization and turnover of inositol phosphates in human neuroblastoma SK-N-SH cells were studied. Caffeine inhibited both the rise in cytosolic Ca2+ concentration ([Ca2+]i) evoked by muscarinic receptor agonists and the total production of inositol phosphates in a dose-dependent manner, but to different extents. At 10 mM, caffeine inhibited agonist-evoked generation of inositol phosphates almost completely, whereas the agonist-evoked [Ca2+]i rise remained observable after caffeine treatment, in the absence or presence of extracellular Ca2+. Raising the cytosolic cAMP concentration increased the carbachol-induced [Ca2+]i rise, and this effect was abolished in the presence of caffeine. Our data suggested that caffeine may exert two effects on receptor-controlled Ca2+ mobilization: 1) inhibition of inositol phosphate production, 2) augmentation of the size of the releasable Ca2+ pool by elevating cytosolic cAMP concentration.
authors.affiliation: Department of Microbiology, Soochow University, Taipei, Taiwan, ROC. psliu@scu.edu.tw
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Liu
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Tu
authors.forename: Lung-Sen
authors.initials: LS
authors.lastname: Kao
mesh_terms: D003994:Bucladesine / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D010716:Phosphatidylinositols / Q000378:metabolism*
chemical_list: D010716:Phosphatidylinositols; D002110:Caffeine; D003994:Bucladesine; D002118:Calcium