Enzymatic Digestion Technique Influences Regulatory Volume Decrease of Isolated Bovine Chondrocytes

Cell volume regulation has been observed in almost all cell types examined to date. When cells are exposed to hypotonic solutions a quick increase in volume is followed by a more gradual return, termed regulatory volume decrease (RVD). The mechanism associated with RVD depends upon cell type and species, but in bovine chondrocytes the non-selective osmolyte channels are mainly responsible [1]. In a chondrocyte, volume control is critical for the maintenance of metabolism, and biosynthesis. Volume fluctuations can be due to changes in hydrostatic pressure, fluid flows, deformation, and extracellular matrix (ECM) hydration. Alterations in hydration can occur during static loading of articular cartilage or during the early stages of osteoarthritis [1], which have been correlated with changes in cellular metabolism. The swelling behaviour of chondrocytes, and the mechanism by which they sense and respond to changes in their physico-chemical environment, are not well understood [1]. To investigate the effects of osmotic environment on chondrocyte behaviour it is often beneficial to isolate cells from the ECM, which can be achieved by a variety of techniques. To investigate the effect of isolation technique on the swelling behaviour of bovine chondrocytes, two enzymatic digestion techniques were chosen for this study.