Neurohumoral pathways mediating stress-induced changes in rat gastrointestinal transit.

Pharmacologic and surgical procedures were used to define the neurohumoral pathways that mediate stress-induced changes in gastrointestinal transit in the rat. Physical restraint (a validated stressor) resulted in significant inhibition of gastric emptying and small bowel transit but in stimulation of large bowel transit. Most importantly, the results indicate that stress-induced changes in gastrointestinal transit in rats are differentially mediated by sympathetic and parasympathetic efferents of the autononic nervous system and, in part, by opiate pathways but not by the pituitary and adrenal glands. Stress-induced inhibition of gastric emptying is mediated by noradrenergic efferents, whereas stress-induced changes in small and large bowel transit are predominantly mediated by vagal, parasympathetic efferents.