Stomach acid secretion in submissive and aggressive rats.

These studies were conducted to determine whether aggressive and submissive behavior are related to either an increase or a decrease in gastric secretion. In Experiment 1, intruder rats placed in an established male-female colony and attacked by a dominant alpha male secreted less acid than intruders exposed to nonaggressive males and females. In Experiment 2, intruders exposed to attack and subsequently returned to the encounter site, but protected from physical attack, still demonstrated a gastric hyposecretion. Rats with chronic gastric cannulas in Experiment 3 also revealed an acid inhibition when attacked and later when exposed to, but protected from, attack. Both intruders and attacking males were prepared with gastric cannulas in Experiment 4. Both demonstrated secretory inhibition following attack and attack-protected sessions. The inhibitory effect was greater and more persistent for intruder rats than for aggressive rats. The inhibition occurring during the attack-protected sessions may have been mediated by some conditioning processes. Other associative mechanisms are discussed, and the present results are also compared with those of relevant clinical reports.