Components |
AF |
NP |
Water |
60-70 %, no change with age |
90 % at birth |
80 % at age 20 |
70 % at older age |
Collagens (collagen I, collagen II, collagen X- collagen X is produced by the degenerated disc which has very poor mechanical properties) |
Only collagen II, 50-60 % with (dry weight) |
Only collagen I, 15-20 % with (dry weight) |
Little change with age |
Little change with age |
PGs (Proteoglycans) |
15-20 % with (dry weight) |
65% with (dry weight) |
Little change with age |
Little change with age |
Non- collagenous proteins and elastin |
5-25% with (dry weight) |
20-45% with (dry weight) |
Little change with age |
Little change with age |
Extracellular enzymes, age pigments, cells |
Minor remainder |
Minor remainder |