Figure 1. Effect of mechanical strain on chondrocyte metabolism. (A) The cell appearance in the cultures with (b,d) or without (a,c) 24-hour mechanical strain of 12% elongation at day 4 (a,b) and day 12 (c,d). Bar = 3 µm. The magnified appearance of a dividing cell is shown in the inset. The syntheses of DNA per well for proliferating chondrocytes (on day 4) (B), proteoglycan (C), and collagen (D) per well for matrix-forming chondrocytes (on day 12) were determined as described in MATERIALS & METHODS. = negative stress; = positive stress. Mean ± SD, n = 3, *p < 0.05.