Ulcer Length Research Articles

Activity stress effects on voluntary ethanol consumption, mortality and ulcer development in rats

The present study was designed to investigate the relationship between activity stress, alcohol consumption and ulcer proliferation. Ethanol consuming rats were initially divided into low, medium or high ethanol preferring groups on the basis of daily ethanol intake (g/kg/day). Following a habituation period in activity cages, animals were fed for 1 hr per day. Access to both water and ethanol remained ad lib. Yoked control home cage animals were fed the same amount of food consumed by their wheel-housed partners. This procedure continued until wheel-housed animals died, at which time thwy and their yoked home cage control partners were examined for ulcers. Results indicated that in contrast to the yoked controls, only the high ethanol-preferring rats reduced their ethanol consuption. Although no differences were apparent in ulcer frequency (mean number of ulcers per rat) or severity (mean cumulative ulcer length in millimeters), animals exposed to ethanol had a lower ulcer incidence (number of rats per group developing ulcers) and mortality rate than non-ethanol exposed animals.

Human milk-derived growth factor prevents duodenal ulcer formation.

Human milk was fractionated to obtain a partially purified growth factor preparation. The growth factor in this fraction, designated as human milk growth factor III, exhibits chromatographic and biological characteristics similar to epidermal growth factor-urogastrone. Pretreatment of mice with human milk growth factor III significantly reduces the incidence, number, total length, and severity score of cysteamine-induced duodenal ulcers.

Early weaning predisposes rats to exacerbated activity-stress ulcer formation

Rats were weaned early (Day 15), normally (Day 21) or late (Day 27). When they reached 200 g (±10) they were placed into the activity-stress paradigm. Half the rats in each weaning group were housed in activity-wheel cages and fed only 1 hr each day. The remaining rats served as food-yoked home cage controls and were fed only that amount of food eaten by their wheel-housed partners. Early weaned rats ran more than normally or late weaned animals. Early weaned rats also died at a faster rate and exhibited a significantly greater cumulative ulcer length than did normally or late weaned rats, although ulcer incidence did not differ between the groups. No ulcers occurred in home cage control rats. Early maternal deprivation may generally predispose rats to stress-induced gastrointestinal disease, whether or not such disease has an acid etiology.

Effects of catecholamine agonist and antagonist drugs on acute stomach ulceration induced by medial hypothalamic lesions in rats

In order to investigate the involvement of catecholamines (CAs) in acute stomach ulceration induced by hypothalamic lesions, rats were given bilateral electrolytic anodal lesions in the medial hypothalamus followed by a single subcutaneous injection of CA agonist or antagonist drugs. As in previous studies, lesioned rats that received no post operative drug treatment showed extensive gastric damage when examined 24 hr after the brain lesion. Chlorpromazine, amphetamine, desipramine and isoproterenol caused significant reductions in the extent (total length) and/or number of erosions induced by the brain lesion. Haloperidol and propranolol did not seem to affect ulcer formation. Clozapine increased the number but not the total length of ulcers. Phentolamine, alone or in combination with propranolol, significantly increased both the number and total length of lesion-induced ulcers. Similarities between these results and those reported for most of these drugs in the context of ulcers induced by various experimental stress procedures suggest a degree of commonality between acute stress ulcers and ulcers induced by hypothalamic lesions. The overall pattern of results obtained is also consistent with evidence indicating a protective role for catecholamines in acute ulcer formation.