Reduced fat stores after early weaning: A correlate of vulnerability to stress ulcers

Rats prematurely weaned at day 15 (15w) are more susceptible to restraint-induced gastric erosions (RGEs) than rats weaned normally at day 21 (21w). Increased RGE susceptibility is linked to nutritional changes occurring during premature weaning and to a disturbance of temperature regulation during restraint. Here we examine the hypotheses that: (a) premature weaning leads to decreases in fat stores, (b) a decrease in fat stores is associated with the occurrence of RGEs and hypothermia. Wet weights of white and brown adipose tissue deposits were determined in 30 day old 15w and 21w rats before or subsequent to food deprivation and restraint. In additional 21w animals we excised bilateral inguinal fat depots or interscapular brown adipose tissue (BAT) prior to food deprivation and restraint. Stomachs were examined for the presence of RGEs. Early weaned (15w), but not 21w rats became hypothermic and developed RGEs. White and brown adipose tissue weighed significantly less in 15w rats than in 21w rats, and 15w rats used a larger percentage of white adipose tissue. Excision of BAT, but not white adipose tissue increased RGE susceptibility of 21w rats. We conclude that the occurrence of RGEs in 15w rats is associated with decreased fat stores. Furthermore, the results suggest that BAT protects against RGE formation.