Disappearance of an inhibitory factor of exocrine pancreas secretion in chronic alcoholic dogs.

In non-alcoholic dogs the exocrine pancreatic response to caerulein, but not to urecholine or secretin alone, was increased by atropine. This indicated a pancreatic inhibition triggered by the caerulein stimulation and blocked by atropine. The present aim was to examine whether atropine had a similar action on the caerulein-stimulated pancreatic secretion in dogs submitted to long-term alcohol feeding. Alcohol-fed dogs showed an increased volume and bicarbonate response to submaximal caerulein but a non-modified protein response as compared with the responses before alcohol adaptation. The elevated water and bicarbonate responses were not further enhanced by atropine, which, in contrast, enhanced the responses of normal dogs to such an extent as to equalize their responses with those of the treated dogs. Atropine, 5 micrograms X kg-1 X h-1, enhanced similar protein responses to submaximal caerulein more in normal than in alcohol-fed dogs, but with an eightfold higher atropine dose no enhance was produced in dogs alcohol-fed for 36 months. This dose of atropine still evoked a small and similar enhancement in the normal and 9-month-treated dogs. The enhancing action of atropine on caerulein-stimulated secretion, present in normal dogs, hence diminishes and finally disappears as a result of chronic alcohol feeding.