Abstract
An increase in intracellular calcium concentration stimulated by anti-CD2 or CD3 antibodies has been measured with Fura-2 in P28 cells, a human CD4+ T cell clone. This intracellular calcium increase was sensitive to membrane potential changes, being increased when the cells were hyperpolarized and decreased when they were depolarized. The intracellular calcium increase was inhibited by nitrendipine (1-50 microM). Nitrendipine also induced a depolarization of the cells, due to the blockade of a potassium conductance. The inhibition of the calcium increase caused by nitrendipine could be partially reversed by hyperpolarizing the cells with valinomycin. It is concluded that the effects of nitrendipine on potassium channels may account for a large part of the inhibition that nitrendipine exerts on the calcium increase elicited by CD2 or CD3 stimulation.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Antibodies, Monoclonal
-
Antigens, CD / immunology
-
Antigens, Differentiation, T-Lymphocyte / immunology
-
CD2 Antigens
-
CD3 Complex
-
CD4-Positive T-Lymphocytes / drug effects
-
CD4-Positive T-Lymphocytes / metabolism*
-
CD4-Positive T-Lymphocytes / ultrastructure
-
Calcium / metabolism*
-
Calcium Channels / metabolism
-
Cell Membrane / metabolism
-
Cells, Cultured
-
Fura-2
-
Humans
-
Membrane Potentials / drug effects
-
Membrane Potentials / physiology
-
Microscopy, Fluorescence
-
Nitrendipine / pharmacology*
-
Potassium Channels / metabolism
-
Receptors, Antigen, T-Cell / immunology
-
Receptors, Immunologic / immunology
Substances
-
Antibodies, Monoclonal
-
Antigens, CD
-
Antigens, Differentiation, T-Lymphocyte
-
CD2 Antigens
-
CD3 Complex
-
Calcium Channels
-
Potassium Channels
-
Receptors, Antigen, T-Cell
-
Receptors, Immunologic
-
Nitrendipine
-
Calcium
-
Fura-2