SIGNIFICANCE OF PRIMARY SPONGIOSA IN TIBIA TEST OF GROWTH HORMONE

抄録

The maintenance test and repair test of bovine growth hormone, Lot No.N-2 Teikoku Hormone Mfg.Co., were carried out on male rats of Donryu strain.As growth hormone was appropriately effective in increasing the width of tibia epiphysis cartilage plate and in elongating primary spongiosa, Donryu rats were useful enough to perform tibia test.Histological examination on tibia epiphysis may be indispensable for the bioassay of growth hormone in comparison with body-weight and tail-length.It is harzardous that the width of cartilage plate in tibia test is measured only by means of silver nitrate method, because the vesicular cell layer of cartilage plate elucidated histologically in stained preparations could not be demonstrated by silver nitrate method.Four major criteria, the width of cartilage plate, the length of primary spongiosa, distributing density of small trabeculae and the changes of osteoblasts, are required to be properly estimated in tibia test.Growth hormone may act promptly upon those four places of tibia epiphysis.In particular, the important significance of primary spongiosa in tibia test was discussed.