A model for studying the initiation of normal XXXX in vivo.

@entity3163 @entity1792 @entity730 @entity460 @entity35 @entity3151 @entity1388
1. @entity35 costal cartilage was found to begin to calcify normally when the @entity35 weigh 35-45g. 2. The cartilage is suggested as a model for the study in vivo of mechanisms concerned with normal @entity730 . 3. The model was tested by studying the incorporation of @entity1388 into the mineral deposited in the tissue. 4. The percentage of inorganic material in cartilage rose from approx. 3% of the dry weight in the uncalcified tissue to 62% in the tissue from @entity35 weighing 300g. 5. Mineral deposited had a @entity460 / @entity3151 molar ratio of 1.65. 6. After the oral administration of @entity3163 to @entity35 , @entity1388 was incorporated into cartilage mineral. 7. The concentration of @entity1388 in cartilage ash increased rapidly with @entity730 and the mineral became more highly fluoridated than the corresponding rib bone. 8. Fluoridated mineral showed a marked decrease in @entity1792 concentration.
