Influence of species and anatomical location on chondrocyte expansion

<p>Abstract</p> <p>Background</p> <p>Bovine articular cartilage is often used to study chondrocytes <it>in vitro</it>. It is difficult to correlate <it>in vitro </it>studies using bovine chondrocytes with <it>in vivo </it>studies using other species such as rabbits and sheep. The aim of this investigation was to study the effect of species, anatomical location and exogenous growth factors on chondrocyte proliferation <it>in vitro</it>.</p> <p>Methods</p> <p>Equine (EQ), bovine (BO) and ovine (OV) articular chondrocytes from metacarpophalangeal (fetlock (F)), shoulder (S) and knee (K) joints were cultured in tissue culture flasks. Growth factors (rh-FGFb: 10 ng/ml; rh-TGFβ: 5 ng/ml) were added to the cultures at days 2 and 4. On day 6, cells were counted and flow cytometry analysis was performed to determine cell size and granularity. A three factor ANOVA with paired Tukey's correction was used for statistical analysis.</p> <p>Results</p> <p>After 6 days in culture, cell numbers had increased in control groups of EQ-F, OV-S, OV-F and BO-F chondrocytes. The addition of rh-FGFb led to the highest increase in cell numbers in the BO-F, followed by EQ-F and OV-S chondrocytes. The addition of rh-TGFβ increased cell numbers in EQ-S and EQ-F chondrocytes, but showed nearly no effect on EQ-K, OV-K, OV-S, OV-F and BO-F chondrocytes. There was an overall difference with the addition of growth factors between the different species and joints.</p> <p>Conclusion</p> <p>Different proliferation profiles of chondrocytes from the various joints were found. Therefore, we recommend performing <it>in vitro </it>studies using the species and site where subsequent <it>in vivo </it>studies are planned.</p