Genetic predisposition to stomach ulceration in emotionally reactive strains of rats

Abstract

A simplified method of inducing ulceration by stress was applied to two strains of nits selectively bred for high and low emotionality in the open-field test. Contrary to a previous report, the severity of stomach ulceration as assessed by a refined technique of stomach examination was found to be greater in the emotionally reactive strain (MR) than in the nonreactive strain (MNR). It was argued that the physiological mechanism underlying the higher emotional elimination of the MR strain reflects greater parasympathetic discharge of the sacral division under certain stressful conditions and that the parasympathetic hyperactivity may partly account for the genetic predisposition of the MR strain to stress ulceration.