Changes in connective tissue components in ulcer tissue during the healing process of acetic acid ulcer in rats

In order to elucidate the role of connective tissue components on the repair of ulcerated regions, quantitative changes in chemical components in ulcer tissue during the healing process were investigated in acetic acid-induced ulcer in rats. The ulcer index showed a peak on the 5th day after the operation, declined rapidly and maintained a slight level the 15th to the 60th days, without a complete recovery. In ulcer tissue, sialic acid and hexosamine remarkably increased in the early stages of healing, showing a peak on the 5th day. The patterns of time course of changes in both components ran almost parallel with those in the ulcer index. Uronic acid maintained slightly higher levels than normal levels the 5th to the 60th days. Hydroxyproline continued to increase with the time course from the 25th day. When acid mucopolysaccharides in ulcer tissue were isolated into various fractions, there were increases in hyaluronic acid on the 5th day, in chondroitin sulfate A and chondroitin sulfate C on the 30th day and chondroitin sulfate B on the 60th day, respectively. Significance of changes in these components in the healing process is discussed.