@article{oai:kanazawa-u.repo.nii.ac.jp:00013065, author = {Hashii, Minako and Shuto, Satoshi and Fukuoka, Masayoshi and Kudo, Takashi and Matsuda, Akira and Higashida, Haruhiro}, issue = {2}, journal = {Journal of Neurochemistry}, month = {Jul}, note = {We synthesized analogs modified in the ribose unit (ribose linked to N1 of adenine) of cyclic ADP-ribose (cADPR), a Ca2+-mobilizing second messenger. The biological activities of these analogs were determined in NG108-15 neuroblastoma × glioma hybrid cells that were pre-loaded with fura-2 acetoxymethylester and subjected to whole-cell patch-clamp. Application of the hydrolysis-resistant cyclic ADP-carbocyclicribose (cADPcR) through patch pipettes potentiated elevation of the cytoplasmic free Ca2+ concentration ([Ca2+]i) at the depolarized membrane potential. The increase in [Ca2+]i evoked upon sustained membrane depolarization was significantly larger in cADPcR-infused cells than in non-infused cells and its degree was equivalent to or significantly greater than that induced by cADPR or β-NAD+. 8-chloro-cADPcR and two inosine congeners (cyclic IDP-carbocyclic-ribose and 8-bromo-cyclic IDP-carbocyclic-ribose) did not induce effects similar to those of cADPcR or cADPR. Instead, 8-chloro-cADPcR together with cADPR or cADPcR caused inhibition of the depolarization-induced [Ca2+]i increase as compared with either cADPR or cADPcR alone. These results demonstrated that our cADPR analogs have agonistic or antagonistic effects on the depolarization-induced [Ca2+]i increase and suggested the presence of functional reciprocal coupling between ryanodine receptors and voltage-activated Ca 2+ channels via cADPR in mammalian neuronal cells. © 2005 International Society for Neurochemistry., 金沢大学大学院医学系研究科}, pages = {316--323}, title = {Amplification of depolarization-induced and ryanodine-sensitive cytosolic Ca2+ elevation by synthetic carbocyclic analogs of cyclic ADP-ribose and their antagonistic effects in NG108-15 neuronal cells}, volume = {94}, year = {2005} }