Is there a correlation between age and D-aspartic acid in human knee cartilage?
L-Aspartic acid (L-Asp) is one of the fastest racemizing amino acids such that the abnormal D-form (D-Asp) has been found in stable biological human tissues such as dentin in teeth, eye lens and brain. Earlier reports showed that there was a linear correlation between age and D-Asp in teeth. We have previously reported that significant levels of D-Asp were found in normal and osteoarthritic knee cartilage. Since cartilage is a slow regenerating tissue, we hypothesized that D-Asp should accumulate in knee cartilage and that there might be a correlation between the age of the person and the amount of D-Asp found in cartilage. Our analysis of approximately 100 samples of normal knee cartilage showed that there are detectable amounts of D-Asp (2-4% of total Asp) in knee cartilage. However, there was only a slight correlation (r = 0.35) between the age of the person and the amount of D-Asp (nmoles/g). Surprisingly, there was a better correlation between age and the amount of D-Asp in the male subjects (r = 0.57) than in the female subjects (r = 0.21).
Fisher
G
G
Department of Chemistry, Barry University, Miami Shores, Florida 33161, USA. gfisher@mail.barry.edu
Lopez
S
S
Peterson
K
K
Goff
T
T
Philip
I
I
Gaviria
R
R
Lorenzo
N
N
Tsesarskaia
M
M
D000375:Aging / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D002356:Cartilage / Q000378:metabolism*; D026603:D-Aspartic Acid / Q000378:metabolism*; D003804:Dentin / Q000378:metabolism; D005123:Eye / Q000378:metabolism; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000378:metabolism*; D008297:Male; D012727:Sex Characteristics
D026603:D-Aspartic Acid