Inositol-1,4,5-trisphosphate and non-hydrolysable GTP analogue induced calcium release from intracellular stores of the Helix pomatia neurons.
1. Cytoplasmic Ca2+ concentration ICaIin and membrane potential of single Helix pomatia neurons was studied by Fura-2 fluorescence measurement and conventional current clamp methods. 2. Intracellular injection of inositol-1,4,5-trisphosphate (IP3) and nonhydrolysable GTP analogue (Gpp/NH/p) led to a rise of ICaIin; in contrast, GTP injection did not cause significant ICaIin changes. 3. We suggest that both IP3 and Gpp/NH/p directly activated Ca release from intracellular stores.
Belan
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PV
A. A. Bogomoletz Institute of Physiology, Academy of Science of Ukranian S.S.R., Kiev.
Osipenko
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ON
Tepikin
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AV
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005456:Fluorescent Dyes; D016257:Fura-2; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology*; D006372:Helix, Snails / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*
D005456:Fluorescent Dyes; D006165:Guanylyl Imidodiphosphate; D015544:Inositol 1,4,5-Trisphosphate; D006160:Guanosine Triphosphate; D002118:Calcium; D016257:Fura-2