[Receptive relaxation of the canine stomach].

Receptive relaxation of the stomach by feeding was studied in 5 conscious dogs by means of chronically implanted force transducers on the gastric body and antrum. It was found that only the gastric body but not antrum relaxed by feeding, and magnitude of the relaxation of the gastric body was linearly related to the volume (5, 10 and 20 g/kg) of test meals, given once or in multiple times. Secondly, in the study of pharmacological blockers, it was found that atropine, hexamethonium and phentolamine significantly inhibited relaxation, while naloxone and proglumide significantly suppressed relaxation in 3 dogs. Propranolol and domperidone did not influence on receptive relaxation. It is concluded that receptive relaxation of the stomach is mainly mediated through a cholinergic reflex, however, involvement of neurotransmitters other than acetlycholine is suggested in the regulation of receptive relaxation.