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Mobilization of intracellular calcium stores participates in the rise of [Ca 2+ ] i and the toxic actions of the HIV coat protein GP120
Author(s) -
Medina Igor,
Ghose Sraboni,
BenAri Yehezkel
Publication year - 1999
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.1999.00550.x
Subject(s) - ryanodine receptor , dantrolene , intracellular , calcium in biology , thapsigargin , calcium , microbiology and biotechnology , chemistry , nmda receptor , voltage dependent calcium channel , biophysics , biochemistry , receptor , biology , organic chemistry
The HIV envelope glycoprotein, GP120, increases intracellular Ca 2+ concentration and induces degeneration of human and animal neurons in culture. Using patch‐clamp recordings and Ca 2+ imaging techniques, we have now examined the contribution of intracellular stores of calcium in the effects of GP120. We report that in rat hippocampal neuronal cultures, GP120 induces a dramatic and persistent increase in [Ca 2+ ] i which is prevented by drugs that either deplete (caffeine, carbachol, thapsigargin) or block (dantrolene) Ca 2+ release from intracellular stores. In contrast, N‐methyl‐ d ‐aspartate (NMDA) receptors or voltage‐dependent calcium channels do not participate in these effects, as: (i) the increase in [Ca 2+ ] i was not affected by NMDA receptor antagonists or calcium channel blockers; and (ii) and GP120 did not generate any current in whole‐cell recording. Dantrolene, a ryanodine stores inhibitor, also prevented neuronal death induced by GP120. Our results show that the GP120‐induced rise in [Ca 2+ ] i originates from intracellular calcium stores, and suggest that intracellular stores of calcium may play a determinant role in the pathological actions of GP120.