Developmental changes in the collagens and some collagenolytic activities in bovine dental pulps

Collagen concentration was fairly low in young bovine 3rd premolar pulps, about 9 per cent by dry weight of pulp in stage I, but it increased consistently up to more than 25 per cent at stage V as the pulp matured. The ratio of type III to type I collagen similarly increased from 13 per cent at stage I to 32 per cent at stage V. Both collagenase and possibly collagenolytic neutral peptidases showed significantly high activity in the early stage of pulp development where the rate of collagen synthesis was also elevated. Higher rates of both collagen synthesis and its degradation might explain the low concentration and content in the early stage of pulp development.