Histological and Histochemical Studies on the Costal Cartilage of Sprague Dawley Rats

Histological and histochemical studies were carried out on the costal cartilage of Sprague Dawley rats at 10. 18. 30, and 54 weeks of age. Histological changes were characterized by vacuolization. atrophy, enlargement or disappearance of chondrocytes, and loss of homogeneity of the matrix. These changes were seen from 10 weeks of age, and progressed with increasing age. On the other hand, proliferation of chondrocytes from the perichondrium was seen from 30 weeks of age. Acidic mucopolysaccharides decreased with increasing age, and increased in the area of chondrocyte proliferation described above. (J Toxicol Pathol 2: 261•`266, 1989)