Effects of Age on the Histochemical Characterization of Costal Cartilage

Abstract

Experiments on 5 groups of puppies ranging in ages from 3 weeks to 30 weeks were described for the purposes of 1) determining at what age the precipitation of Ca salts from the body fluids begins in costal cartilages; 2) estimating the amount of calcification in order to correct the cartilage tissue for the formed bone salts and 3) presenting histochemical patterns of the cartilages after they were corrected for this calcification. It was shown that a mean of 12 m. eq. of Ca was present/100 g. of costal cartilage solids in all puppies up to 12 weeks of age and this amount was considered to represent the Ca concentration in cartilage before any calcification has taken place. The Ca content above this mean amount was used to indicate the formation of extra Ca salts in the tissue. The formation of bone salts was very erratic and age was not the sole reason for the extend of the calcification. The estimation of the amount of bone salts formed in the costal cartilages of puppies up to 30 weeks of age is described and discussed. Assuming the bone salts to be hydroxyl apatite, methods were described whereby the analytical data on the cartilage tissues were corrected for the bone salts deposited and the histochemical patterns for the bone-salt-free tissues were presented and discussed.