Abstract
The aging changes of the incorporations of radiosulfate (35SO4) into the tracheal cartilage were studied in several litters of mice at various ages, from embryos to postnatal 1 year by light microscopic radioautography. The results show that silver grains indicating the incorporations of radiosulfate were found over the cartilage matrices and the cartilage capsules in the hyaline cartilages of the tracheae of perinatal mice. The grain density was at the maximum at fetal day 19, then decreased from fetal day 19 to postnatal day 1, 3, 7, 14 and 30. The silver grains in the perinatal animals aged at postnatal day 1 and 3, moved from the internal layer to the external layer of the cartilage and from the interterritorial matrix to the territorial matrix and the cartilage capsule. No silver grains were found in the animals aged from 1 to 12 months. From these results, it is concluded that the radiosulfate was incorporated into sulfated complex carbohydrate in the cartilage matrices and the pattern of incorporation in the tracheae decreased with the aging of animals.
