[Effect of DGAVP and Org2766 on intracellular free Ca2+ concentration in dissociated brain cells]

Intracellular free calcium concentration ([Ca2+]i) was measured with Fura-2 in freshly dissociated brain cells isolated from newborn (1-2 day) mouse pups using AR-CM-MIC cation measurement system, and the effects of DGAVP and Org2766 on the changes in [Ca2+]i induced by the protein synthesis inhibitor anisomycin (ANI) were studied. The results indicate that anisomycin caused dose-dependent increases in [Ca2+]i; and DGAVP itself showed no significant effect on [Ca2+]i, but an appropriate dose of DGAVP antagonized the increases induced by the selective dose-range of ANI, suggesting that the antagonism of ANI-induced inhibition of protein synthesis by DGAVP was likely achieved by preventing ANI from increasing [Ca2+]i, but this mechanism did not apply to the other neuropeptide Org2766. Therefore, we suppose that the mechanism of the two neuropeptides are different in terms of their effect on intracellular free calcium concentration.