agents retard healing by their anti-inflammatory and inhibitory actions on mucopolysaccharide synthesis (2). Retinoic acid reverses the healing retardation action of anti-inflammatory agents (13).
Active retinoic acid homologs studied in the present paper promote wound healing by increasing granuloma mass.
The healing-promoting action of these active retinoic acid homologs is further evidenced by the increase of hydroxyproline and hexosamine contents of the granuloma (Tables 111-VI), Hydroxyproline is an important constituent of collagen, which is an essential component of connective tissue. Hexosamine is a component of mucopolysaccharide, and the role of mucopolysaccharide in healing was extensively discussed previously (2). As shown in Tables 111-VI, both the hydroxyproline and hexosamine contents were increased in the granuloma with either one of the active compounds. This fact indicated that these compounds increased connective tissue regeneration. However, the amount of hydroxyproline or hexosamine per unit of weight of granuloma of the experimental was lower than that of the control. This fact indicated that these active compounds also stimulated inflammation.
It is suggested that active retinoic acid homologs, like retinol, promote healing by inducing inflammation and increase mucopolysaccharide and collagen synthesis mechanisms of action.