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Updated: Aug 11, 2026

Mechanical Stimulation-induced Calcium Wave Propagation in Cell Monolayers: The Example of Bovine Corneal Endothelial Cells
Published on: July 16, 2013
Calcium entry, mobilization, and extrusion in postcapillary venular endothelium exposed to bradykinin
M Ziche1, D Zawieja, R K Hester
1Microcirculation Research Institute, Texas A & M University Health Science Center, College Station 77843.
Abstract:
The effect of bradykinin (BK) on cytosolic calcium in coronary venular endothelial cells (CVEC) was studied using the intracellular calcium indicator indo 1. At normal extracellular calcium levels, CVEC responded to BK at concentrations as low as 0.1 pM; maximum cytosolic calcium spikes occurred at 10 nM. In calcium-free medium, poststimulation cytosolic calcium concentration returned to levels below prestimulation values, implying that BK modulates calcium extrusion mechanisms that are normally masked by calcium influx into the cell. To test this hypothesis, we depleted internal stores of calcium using two approaches: preconditioning or blockade of the endoplasmic reticulum calcium pump with the sesquiterpene lactone, thapsigargin. Depletion by preconditioning consisted of two prior doses of BK followed by a third stimulus of the agonist. Under these conditions, the final dose of BK caused a fall, rather than rise, in cytosolic calcium. Thapsigargin blocked the endoplasmic reticulum calcium pump, leading to a steady-state rise in intracellular calcium concentration. Subsequent exposure of these cells to BK also led to a fall in cytosolic calcium. The preconditioning and thapsigargin studies are consistent with a modulation of calcium extrusion processes by BK in CVEC. The signals responsible for this modulation are unknown.
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