Age-related changes in D-aspartic acid of rat teeth.
In addition to L-aspartic acid, D-aspartic acid was detected in the protein (collagen) of rat teeth. The content of D-aspartic acid in rat molars increased significantly with age, showing a close correlation with age (r = 0.965-0.993), whereas in rat incisors D-aspartic acid did not increase. This suggests that there is little metabolic activity in rat molars after their formation. The amount of D-aspartic acid present in molars of a single rat was in the order first molars > second molars > third molars. This indicates that the amount of D-aspartic acid is higher in teeth formed earlier, corresponding to the time of their formation. The rate of racemization in rat molars was about ten-fold higher than that in human dentin, suggesting the importance of body temperature in the rate of racemization. These findings also suggest that D-aspartic acid is present in the teeth of other animals.
Ohtani
S
S
Department of Forensic Medicine, Kanagawa Dental College, Japan.
Matsushima
Y
Y
Ohhira
H
H
Watanabe
A
A
D000367:Age Factors; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D002849:Chromatography, Gas; D003094:Collagen / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry; D006801:Humans; D007180:Incisor / Q000737:chemistry; D008963:Molar / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014070:Tooth / Q000033:anatomy & histology / Q000737:chemistry* / Q000254:growth & development
D000596:Amino Acids; D001224:Aspartic Acid; D003094:Collagen