BONE RESORPTION IN TISSUE CULTURE 



617 



21 OB-^ \ 



Fig. 19. Se\cii-da) control calvarium (statioiiai) tubes gassed witli 95 per 

 cent O2 + 5 per cent COo). Note resorption (R) in median suture area. (X 

 14.) • 



Fig. 20. Seven-day culture containing 5 X 10-^ m sodium malonate (sta- 

 tionary tubes gassed with 95 per cent Oo + 5 per cent CO2 ) . Note inhibition 

 of resorption. (X 14.) 



Fig. 21. , Histological section through control calvarium maintained in cul- 

 ture for 9 days. Note multinucleated osteoclast (OCL) at edge of original bone 

 spicule (OB). (X 325.) 



Fig. 22. Histological section through 9-day culture exposed continuously to 

 5 X 10~2 M sodium malonate. Note layer of new osteoid (O) on surface of 

 original bone (OB). (X 325.) 



period, amounting to 8 to 19 times the total citric acid content of 

 the original calvaria ( Kenny et ah, 1959 ) . 



Effect of Parathyroid Extract 



Recently, we have found that it is possible to partially inhibit the 

 resorption of bone in response to oxygen by eliminating the embryo 

 extract component of the supernatant. Surprisingly, with this new 

 culture medium (80 per cent horse serum and 20 per cent Gey's 



