抄録
For the purpose of increasing our knowledge concerning the morphologic aspects of the effects of insulin on a chondrogenesis and a micromelia, tibiotarsi of chick embryos injected with a single dose of 4 units of insulin into yolk sac on the 5th day of incubation were studied by the light microscope using histochemical methods. Two days after insulin treatment, the anlage of the tibiotarsus showed the imperfect differentiation into cartilage. The prechondroblasts failed to accumulate glycogen in the cytoplasm. Although the normal-like chondrogenic activity occured in the perichondrium after 5 days of the injection, the cells in the central areas of the epiphysial plate showed imperfect differentiation into chondroblasts and some of them were degenerated. The degenerative alterations in the central areas of the epiphysial plate 7 days after the treatment became more severe than the previous stage. After 13 days of the injection the degenerated tissues in the central areas were completely replaced by myeloid tissues. It could be deduced from the above that the failure to form epiphysial plate in insulin-treated chick embryos is due to the reduced interstitial growth, thus causing micromelia.
