THE LONGITUDINAL GROWTH OF TIBIA IN ESTRADIOL-TREATED AND RESTRICTEDLY FED IMMATURE MALE-RATS

The effect of oestradiol administration and restricted feeding on long itudinal tibia growth was investigated in immature male rats. The rest rictedly fed animals had a significantly longer tibia, greater thickne ss of the growth plate, faster rate of longitudinal tibial growth as w ell as the greater rate of [methyl-H-3]thymidine incorporation into th e growth plate of the tibia compared with oestradiol-treated animals. The results indicate that, in immature male rats, exogenous oestradiol can decrease the longitudinal growth of the tibia (at least partly du e to inhibition of cell proliferation in the growth plate) independent ly of its anorexic effect.