Effects of local administration of insulin-like growth factor-I on mandibular condylar growth in rats.
Endochondral bone formation observed at the mandibular condyle is regulated by various growth factors including insulin-like growth factor-I (IGF-I). In this paper, we describe a method for the local administration of IGF-I to the bilateral mandibular articular cavities of 3- and 12-week-old rats, and the effects of IGF-I on endochondral bone formation by histomorphometric techniques. In 3-week-old IGF-I-treated rats, three days after administration, an increase in bone tissue was found in the area of the subchondral cancellous bone layer. In 12-week-old IGF-I-treated rats, three days after administration, an increase in the thickness of the condylar cartilage and a decrease in bone tissue were observed in the area of the subchondral cancellous bone layer. This study revealed that the local administration of IGF-I on mandibular condyle caused different histological changes between growth and maturation periods. These results indicated that the effects of IGF-I on endochondral bone formation in the mandibular condyle were age-dependent.
Itoh
Kouichi
K
Maxillofacial Orthognathics, Maxillofacial Reconstruction Division of Maxillofacial/Neck Reconstruction Graduate School, Tokyo Medical and Dental University, Japan. k-itoh.mort@tmd.ac.jp
Suzuki
Shoichi
S
Kuroda
Takayuki
T
D000367:Age Factors; D000818:Animals; D020219:Chondrogenesis / Q000187:drug effects; D006801:Humans; D007270:Injections, Intra-Articular; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage* / Q000494:pharmacology*; D008297:Male; D008335:Mandibular Condyle / Q000187:drug effects* / Q000254:growth & development; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology
D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I