Figure 4.

PTHrP haploinsufficiency circumvents the effects of phosphate restriction on hypertrophic chondrocyte apoptosis in vivo. A, TUNEL labeling was performed on wild-type and PTHrP +/− mice fed a control (chow) or low phosphate diet (low Pi diet) from days 18 to 24. B, TUNEL positive cells were counted in the distal 2 rows of the hypertrophic chondrocyte columns. Data are representative of 3 mice for each genotype and diet. *P < .05, significantly different from wild-type mice fed control diet. Arrowheads indicate TUNEL positive hypertrophic chondrocytes.