Comparison of regional bone blood flow in areas with differing osteoblastic activity in the rabbit tibia

The relationship between regional bone blood flow (measured using the hydrogen washout method) and regional osteoblastic activity (inferred from presence of osteoblasts on histological sections) was studied in the rabbit tibia. The rate of blood flow in epiphyses with marked osteoblastic activity (0.283 +/- .053 ml/min/ml) was significantly faster than that in epiphyses with minimal activity (0.097 +/- .007 ml/min/ml). Metaphyseal blood flow was significantly faster in areas with marked activity (0.253 +/- 0.040 ml/min/ml) than those with moderate (0.153 +/- .007 ml/min/ml) or minimal (0.126 +/- 0.013 ml/min/ml) osteoblastic activity. Diaphyseal bone blood flow was significantly faster in immature (0.082 +/- 0.005 ml/min/ml) than in mature (0.062 +/- 0.004 ml/min/ml) animals. The results indicate that there is a positive association between regional bone blood flow rate and osteoblastic activity in normal bone.