Changes of serum alkaline phosphatase following mandibular osteotomy in the rat.

Activity of alkaline phosphatase in serum (S-ALP) was characterized and compared with that of non-specific alkaline phosphatase (APase) of hard-tissue origin in the rat. The enzyme was characterized biochemically, and optimal incubation procedures were determined. S-ALP levels were determined before and after mandibular osteotomy combined with different degrees of periosteal reflections. Separation of S-ALP isoenzymes by isoelectric focusing revealed four major bands. A marked decrease of S-ALP activity was seen after osteotomy, and all isoenzymes were affected similarly. After treatment with hyperbaric oxygen, a smaller decrease in S-ALP was seen. S-ALP could be used as a marker for hard-tissue turn-over after surgical procedures.