Immobilization Combined With Ovariectomy And Effect Of Active Vitamin-D3 Analogs In The Rat

We examined the effects of immobilization, estrogen deficiency and the combination of these conditions by photo-microdensitometry and measurement of ash weight of the femur. The present experiment was also undertaken to examine whether 26,27-hexafluoro-1-alpha,25 dihydroxyvitamin D3 [F6-D3] and 2-beta-(3-hydroxypropoxy)1-alpha, 25 dihydroxyvitamin D3 [ED-71], which are newly synthetic vitamin D3 analogues, prevent osteopenia induced by a combination of immobilization and ovariectomy in the rat. The severity of osteopenic changes depended on the extent of immobilization. The changes were more pronounced when ovariectomy was combined with immobilization than ovariectomy alone. F6-D3 showed nearly dose-dependent effect and a significant inhibition of the osteopenic decrease of bone mass. ED-71 significantly inhibited the decrease of bone mass in the osteopenic experiment of hemicordotomy combined with ovariectomy. Pharmacological effective dosages of F6-D3 and ED-71 were considered to prevent the osteopenic decrease of bone mass in the rat.