Abstract
Abstract: A scar tissue caused by surgical operation prcduces several difficulties on orthodontic treatment for cleft lip and palate patients. In this study, the biochemical changes with age and wound healing process in rabbit hard palatal mucosa collagen were investigated.
Collagen crosslink analysis was performed by radiochromatography after NaB3H4 reduction, collagentype analysis by electrophoresis. Amino acid composition and water content were also examined.
In age-related changes, the main reducible crosslink was dihydroxylysinonorleucine (DHLNL) infetus. It decreased with age in the skin, but remained at considerable level in the palatal mucosa.Hydroxylysinonorleucine (HLNL) and histidinohydroxymerodesmosine (HHMD) increased in both tissues.Type III cc Hagen decreased with age in the skin, while in the palatal mucosa it was found at low levelin fetus, then increased rapidly after birth and finally decreased again.
In wound healing, collagen contents were elevated to a plateau in three months, but, hydroxyprolinecontents in insoluble fraction changed continuously. DHLNL was the major crosslink immediatelyafter excision, then HLNL and HHMD increased. These changes resembled those with age. Typedecreased with wound healing. A low water content, much reducible crosslinks and a slightly high levelof type M were characterized in the scar tissue one year after excision.
These results suggest that rabbit palatal mucosa and skin collagens have distinctive features as wellas common patterns in age-related changes and palatal mucosa collagen changes in the similar mechanismboth with age and wound healing.
