Effects of Long-Term Administration of Bendroflumethiazide on Bone Metabolism in the Rat

: 45Ca was injected subcutaneously in 160 g rats kept in metabolic cages. After an adjustment period of 10 days, bendroflumethiazide was given orally for another 10 days. The concentration of 45Ca and the specific activity in the bones was significantly higher in the thiazide treated animals than in controls. The excretion of hydroxyproline decreased slowly during the thiazide administration period. The results suggest that the breakdown of both bone mineral and bone matrix was reduced during bendroflumethiazide administration. Bone matrix metabolism was not normalized until 7 days after cessation of thiazide administration as judged by the time required for reversion of the hydroxyproline excretion.