Figure 1.

COX1/2 expression and regulation in chondrocytes. A, Primary bovine articular chondrocytes or primary bovine growth plate chondrocytes from the reserve zone in serum-free medium received 24 hours of IGF-I (100 ng/mL) or vehicle only. Quantitative real-time PCR was used to determine the copy number of COX-1 and COX-2 mRNA per μg of 18s, n = 4 per sample, P < .001 by Student's t test (compared with vehicle). B, Primary growth plate or ATDC5 cells were incubated with IGF-I or vehicle only as above, and PGE₂ in the medium of cells was quantitated by EIA and normalized to the total number of cells. *, P < .001 by t test (compared with vehicle).