['The aim of this study was to investigate the effects of hypo-osmotically induced calcium (Ca(2+)) transients on the organization of the actin cytoskeleton in articular chondrocytes. The secondary hypothesis tested was that actin restructuring following hypo-osmotic stress is mediated by gelsolin.', 'Isolated porcine chondrocytes were exposed to hypo-osmotic stress, and [Ca(2+)](i)was monitored using laser scanning microscopy. Calcium transients were monitored using fluorescent ratiometric imaging. The intracellular distribution of actin was examined using fluorescent immunohistochemistry and transient transfection with the pEGFP-actin plasmid. The intracellular distribution of gelsolin was investigated using fluorescent immunohistochemistry.', 'Osmotic stress induced transient increases in [Ca(2+)](i)caused reorganization of intracellular actin through a mechanism that required Ca(2+)in the extracellular media. Fluorescence microscopy revealed that gelsolin was colocalized with F-actin immediately following hypo-osmotic stress but dissociated over time.'] Does hypo-osmotic stress induce calcium-dependent actin reorganization in articular chondrocytes?