Carbonic anhydrase activity in isolated osteoclasts

Osteoclasts were isolated from the long bones of chicks by a nylon mesh filtering system. The cell purity, in terms of area of the slide occupied, was on the average 77.5% osteoclasts, 22% aggregated osteoblasts and matrix debris, and 1.5% individual blood and marrow cells. Viability, as measured by cytochalasin-blockable phagocytosis, of up to 99% was obtained. Electron microscopic examination revealed good retention of ultrastructural features. The presence of carbonic anhydrase and acid phosphatase in osteoclasts was verified by selective staining methods; the aggregates were positive for alkaline phosphatase. Carbonic anhydrase activity was 0.89 +/- 0.13 X 10(-4) micro Wilbur-Anderson units per osteoclast, and red blood cells had 0.12 +/- 0.03 X 10(-4) units/cell. Neither calcitonin nor parathyroid hormone influenced the activity of carbonic anhydrase. A review of other hormonal effects on carbonic anhydrase is provided.