concanavalin-a and Ulcer

Growth factors, such as epidermal growth factor and keratinocyte growth factor, have considerable therapeutic potential for repairing mucosal injury in the intestine when given systemically. Recently, several lectins have been shown to have trophic effects on the intestine when given orally. We examined the effects of phytohaemagglutinin (PHA) and concanavalin A (Con-A) on indomethacin-induced intestinal injury in rat. Five-week-old rats were randomized to four groups (n=5), and intestinal injury was induced by indomethacin injection in three of these groups. Elemental diet (ED) feeding was then commenced. The groups were thus ED feeding/indomethacin untreated (control group), ED feeding/indomethacin treated (ED group), 0.1% PHA-supplemented ED feeding/indomethacin treated (PHA group) and 0.1% Con-A-supplemented ED feeding/indomethacin treated (Con-A group). After 7 days of feeding, macroscopic inflammatory scores, mucosal permeability, myeloperoxidase (MPO) activities and cell proliferation were determined. Macroscopic inflammatory scores, mucosal permeability and MPO activities were significantly lower in both lectin groups than that in control group. Twenty-four hour excretion rate of phenolsulphonphthalein was significantly lower in both lectin groups than that in ED group. Cell proliferation of the small intestine was significantly increased by both lectins. Lectin supplementation can induce ulcer healing following indomethacin-induced damage.

Topics: Animals; Cell Division; Concanavalin A; Food, Formulated; Indomethacin; Intestinal Diseases; Intestinal Mucosa; Intestine, Small; Lectins; Male; Permeability; Peroxidase; Phytohemagglutinins; Rats; Rats, Sprague-Dawley; Ulcer

Agglutination of rat urinary bladder epithelial cells by concanavalin A (Con A) has been reported to be an early marker of bladder carcinogenesis. Ulceration of the bladder, induced by cyclophosphamide (CP) or freezing, followed by sodium saccharin in the diet results in the induction of bladder cancer. In the present studies, the agglutination of rat urinary bladder epithelial cells by Con A was shown to be increased during the regenerative hyperplasia following ulceration induced by i.p. CP injection, but it returned to normal levels by Day 21 when the preparative process was nearly complete. This effect correlated quantitatively with the dose of CP. However, if CP administration was followed by sodium saccharin in the diet beginning 14 days after the injection, the agglutinability of bladder cells by Con A persisted. In contrast, agglutination of bladder cells by Con A during regenerative hyperplasia following ulceration induced by freezing was not increased whether sodium saccharin was fed or not. These results indicate that Con A agglutination distinguishes between the regenerative hyperplasia induced by CP or freezing, even though either method followed by sodium saccharin in the diet results in bladder cancer in the rat.

Topics: Agglutination; Animals; Carcinogens; Concanavalin A; Cyclophosphamide; Dose-Response Relationship, Drug; Epithelium; Freezing; Hyperplasia; Male; Rats; Rats, Inbred F344; Saccharin; Ulcer; Urinary Bladder; Urinary Bladder Diseases; Urinary Bladder Neoplasms