title: Type X collagen is not localized in hypertrophic or calcified cartilage in the developing rat trachea.
abstract: Our previous studies have shown that rat tracheal chondrocytes become larger and hypertrophic, and that the cartilage matrix calcifies during development. Type X collagen is a short collagen molecule identified in hypertrophic and calcified cartilage in the growth plate of long bones during endochondral ossification. The present study was designed to investigate the distribution of type X collagen in rat tracheal cartilage during development before and after hypertrophization and calcification. Tracheas from postnatal Wistar rats, newborn, and at 4, 8 and 10 weeks were fixed along with hind limbs from newborn rats. Serial sections were made and adjacent sections were processed for von Kossa staining or immunohistochemistry for type X collagen. In addition, the immunoreactivity to type II collagen was examined as a control. The anti-type X collagen antibody stained hypertrophic and/or calcified cartilage in the newborn rat tibia. The immunoreaction for type X collagen was localized in the uncalcified peripheral region of tracheal cartilage in 4, 8 and 10-week-old rats. In contrast, the anti-type X collagen antibody did not show immunoreactivity to hypertrophic or calcified cartilage in the central region of the 10-week-old rat tracheal cartilage. The present study has suggested that type X collagen is not involved in hypertrophization of chondrocytes or calcification of the matrix in developing rat tracheal cartilage.
authors.affiliation: Second Department of Oral Anatomy, Tohoku University School of Dentistry, Sendai, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sasano
authors.forename: I
authors.initials: I
authors.lastname: Takahashi
authors.forename: I
authors.initials: I
authors.lastname: Mizoguchi
authors.forename: M
authors.initials: M
authors.lastname: Kagayama
authors.forename: H
authors.initials: H
authors.lastname: Takita
authors.forename: Y
authors.initials: Y
authors.lastname: Kuboki
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002113:Calcification, Physiologic / Q000502:physiology*; D002356:Cartilage / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D006984:Hypertrophy; D051381:Rats; D017208:Rats, Wistar; D014132:Trachea / Q000196:embryology / Q000378:metabolism*
chemical_list: D003094:Collagen