Abstract
ABSTRACT Inflation of the cardiac stomach of the cod induced rhythmic contractions of the muscles and a slow increase in stomach volume towards a maximum. After deflation, the stomach remained relaxed and easily distensible for one or more hours. Section of the vagal tracts to the stomach did not change the response. Inflation in vitro produced a somewhat faster relaxation and a much faster recovery to the pre-distended state than occurred in vivo. Stimulation of the cut ends of the vagus raised gastric tone and increased resistance to distension, an effect mediated by cholinergic nerves. Tetrodotoxin and atropine relaxed the stomach so that distension was rapid and the maximal volume increased, revealing slower, possibly myogenic, contractions. The 5-hydroxytryptamine (5-HT) antagonist methysergide, vasoactive intestinal polypeptide (VIP), met-enkephalin and neurotensin did not affect the responses to distension. Somatostatin abolished spontaneous contractions in the resting stomach and lowered gastric tone, but did not further affect the responses to distension. In conclusion, cholinergic nerves maintain gastric tone in the cod. 5-HT neurones are absent in the cod stomach, and there are no indications of a 5-HT/VIP-controlled mechanism operating during distension. The effect of somatostatin differs from that in rainbow trout. For comparison with trout and cod, responses to in vivo gastric distension are also described for the flatfish Scophthalmus maximus, Scophthalmus rhombus, Limanda limanda and Pleuronectes platessa.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
