The effect of gestagens on bone turnover in sheep
SummaryThe effects of two gestagens on bone turnover were investigated in three groups of female sheep comparable in age and weight. Group A (n = 10) was given a single intramuscular injection of 50 mg chlormadinon acetate (CMA), group B (n = 9) received 140 mg medroxyprogesterone acetate (MPA), and control group C (n = 9) received 5 ml physiological NaCI-solution. Plasma progesterone was measured weekly over 3 months. Bone mineral density (BMD) in the right distal tibia and calcaneus were determined every four weeks during the four months of the study duration, using peripheral quantitative computed tomography (pQCT). At the same times total alkaline phosphatase (AP) was determined. No significant changes of BMD were found in the three groups during the four months. Total alkaline phosphatase showed a significant decrease of 36-45% in all groups during the first six weeks. Sheep seem to have a comparable bone metabolism to humans with respect to the short term effect of gestagens, i. e. MPA and CMA.