pubmed-article:640272 | pubmed:abstractText | This study describes an in vitro experimental model of the sphincter at the lower end of the main pancreatic duct in the dog. This model, employing a drop counter to measure the drop rate, monitors the perfusion rate of Tyrode through the sphincter. Acetylcholine (ACh), employed to establish the sensitivity and viability of the isolated sphincter, produced a contraction of the sphincter which was concentration-response related. Saline, as a control, atropine and hexamethonium did not affect the drop rate. Atropine (20 microgram) partially abolished the contraction produced by 50 microgram of ACh; hexamethonium (50 microgram) did not have an effect. Caerulein 50 microgram produced a relaxation of the sphincter; adrenaline 50 microgram a contraction. Both sympathetic and parasympathetic mechanisms seem to play a role in the regulation of sphincteric activity of the main pancreatic duct in dogs. | lld:pubmed |