Lipid composition of two types of chondrocytes in primary culture

Chondrocytes from articular and growth plate cartilage were grown in primary culture. The lipid content, distribution into different types, as well as the fatty acid patterns of these lipids were compared when the cells had reached stationary phase and were synthesizing maximal amounts of proteoglycans. Numerous significant differences were observed, depending on the origin of the chondrocytes. In particular, growth plate chondrocytes showed increased dry weight, increased lipid content (phosphatides and triglycerides), and decreased cholesterol to phosphatide ratio when compared to articular chondrocytes; they also incorporated more of C18:1 and less C16:0 into their major lipid types. Whether these differences arise from specific metabolic regulation or are a consequence of chondrocyte organization in primary culture remains unclear.