A new continuous monitoring system for simultaneous measurements of intracellular calcium and either endothelial permeability or leukocyte extravasation.

Abstract

We have developed a continuous monitoring system that will quantify lymphocyte extravasation or intercellular permeability with intracellular calcium measurements in a single preparation. Human microvascular endothelial cells, human lymphocytes and histamine. Endothelial barrier function and intracellular calcium were examined upon application of either human lymphocytes (1 x 10(5) cells/ml) or histamine (1 microM). Endothelial cells labeled with FURA-2 were examined for both changes in endothelial barrier function and mobilization of intracellular calcium using fluorescence spectroscopy and ratio imaging, respectively. Increases in endothelial intracellular calcium occur in the first minute and are followed by increases in endothelial intercellular permeability to albumin (5-7 min) or lymphocytes (15-20 min). Approximately 60 min following calcium mobilization, there was a second and larger extravasation. The continuous monitoring system expands our understanding of the time course of the permeability and extravasation events to mobilization of endothelial intracellular calcium.