title: Age-related changes in the D-aspartic acid content of the cranial bones in senescence-accelerated mice (SAM).
abstract: We measured the age-related changes in the D/L-aspartic acid ratio (D/L ratio) of cranial bones in two different sublines of senescence-accelerated mice (SAM/Iw): SAMP2/Iw (SAM, prone 2/Iwate) and SAMR1/Iw (SAM, resistant 1/Iwate). In SAM/Iw under 9 months of age, the D/L ratio in SAMP2/Iw was higher than that in SAMR1/Iw (p<0.001). However, in all 12-month old SAM/Iw, whether SAMP2/Iw or SAMR1/Iw, the D/L ratio was higher in males than in females. There were minor differences in the age-related changes in the D/L ratios between different types of cranial bone. In 1-month old SAM/Iw the rectal temperature was similar in both males and females. However from the age of 2 months, there was a divergence, with the rectal temperature measurement in SAMP2/Iw reaching a peak 2 months of age, whereas SAMR1/Iw had the highest temperature readings at 6 months of age. In both SAMP2/Iw older than 2 months, and SAMR1/Iw older than 6 months, the temperature readings tended to gradually decrease with age in both males and females. These results suggest that the differences in D/L-aspartic acid ratios were dependent on the age, gender, and strain of SAM/Iw, but were not dependant on the type of cranial bone studied. It seems likely that these differences may be related mainly to changes in body temperature.
authors.affiliation: Department of Forensic Dental Medicine and Institute for Frontier Oral Science, Kanagawa Dental College, Yokosuka, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Ohtani
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Mieko
authors.initials: M
authors.lastname: Sashima
authors.forename: Masanobu
authors.initials: M
authors.lastname: Satoh
mesh_terms: D000367:Age Factors; D019588:Aging, Premature / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D000818:Animals; D001831:Body Temperature; D026603:D-Aspartic Acid / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D008297:Male; D051379:Mice; D012886:Skull / Q000254:growth & development* / Q000378:metabolism*; D013045:Species Specificity; D013237:Stereoisomerism
chemical_list: D026603:D-Aspartic Acid