GANGLIOSIDES RAISE THE INTRACELLULAR CA2-TYPES( LEVEL IN DIFFERENT CELL)

Total gangliosides from bovine brain at micromolar concentration induc e intracellular Ca2+ increments in a temperature, time and dose depend ent manner when assayed with suspensions of rat macrophages, rat and c hicken neurons, human erythrocytes and liposomes, loaded with the fluo rescent Ca2+ indicator FURA 2. The effect was independent on the endog enous ganglioside composition of the cells and in the case of neurons it was also independent on the differentiation state. Gangliosides do not induce the release of Ca2+ from inner stores. These findings indic ate that the reported inhibition of arachidonic acid release (Bressler , J., et al., (1994) Life Sci., 54, 49-60) and anti-inflammatory prope rties of gangliosides (Correa, S.G. et al., (1991) fur. J. Pharmacol. 199, 93-98) are not due to impairments of Ca2+ nux. The results also s uggest the possibility that the well-known neurotrophic effect produce d by gangliosides on undifferentiated neurons in culture may be due to subtoxic cytosolic Ca2+ increments.