Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9882251 | Archives of Biochemistry and Biophysics | 2005 | 13 Pages |
Abstract
The effect of ceramide on the cytoplasmic Ca2+ concentration ([Ca2+]i) varies depending on the cell type. We have found that in Jurkat human T cells ceramide increases the [Ca2+]i from a thapsigargin-sensitive calcium pool and the subsequent activation of a capacitative Ca2+ entry. This effect occurs both in the presence and in the absence of extracellular calcium. Addition of ceramine, a non-hydrolysable analogue of ceramide, reproduced its effect on the [Ca2+]i ruling out that this is due to the conversion of ceramide to sphingosine. The effect of ceramide was additive to that obtained by sphingosine, but not to the Jurkat T cells specific antibody OKT3. However, different to the latter, ceramide do not induced an elevation of InsP3. The opening of a store operated Ca2+ channel by ceramide was corroborated by experiments of Fura-2 quenching, using Mn2+ as a surrogate for Ca2+ and confirmed by whole-cell recording patch clamp techniques.
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Authors
Claudia Colina, Adriana Flores, Héctor Rojas, Angie Acosta, Cecilia Castillo, MarÃa del Rosario Garrido, Anita Israel, Reinaldo DiPolo, Gustavo Benaim,