Indomethacin-induced inhibition of haversian remodelling in rabbits.

The effect of indomethacin on haversian remodelling in the radius was studied in 16 rabbits. An osteotomy and a saw-cut almost through the bone were made in the middle and distal parts of the right radius, respectively. In order to obtain biological osteosynthesis in the osteotomy and the saw-cut the rabbits were not treated in any way during the following 3 weeks. They were then given either indomethacin or placebo suspensions per os, 10 mg/kg/day for 2 weeks, followed by 5 mg/kg/day for 4 weeks. The extent of haversian remodelling was estimated by calcein and oxytetracycline fluorochrome labels given at the start of the indomethacin treatment and 3 weeks later, respectively. After 2 weeks of indomethacin treatment (10 mg/kg/day) the indomethacin plasma levels were about 0.18 microgram/ml 24 hours after the last dose. Indomethacin treatment significantly (2P less than 0.019) inhibited haversian remodelling as estimated by fluorochrome labelling.