DIGESTIVE MOTILITY IN CARNIVOROUS - NEURO HORMONAL AND PHARMACOLOGICAL REGULATION

After a brief description of the motor patterns observed iri the diges tive tract of the carnivore, the authors developped the respective rol e of digestive hormones in the modulation of such patterns in dogs, re fered to the digestive status. Concerning the hormonal regulation, the re is increasing evidence that many neuropeptides are involved in the regulation of the digestive motility in carnivorous. A typical profile of posprandial activity corresponding to the continuous occurrence of contractions propagated is accompanied by an increase in plasma level of 8 to 10 identified digestive hormones. Four of them (insulin, gast rin, neurotensin and cholecystokinin octapeptide) infused systemically may produce or prolong this typical postprandial pattern suggesting t hat they may play a role in the initiation and duration of this patter n. The fasted state is characterized by the cyclic occurrence of gastr ointestinal motor complexes (MMC) associated with cyclic changes in pl asma levels of motilin, somatostatin, pancreatic polypeptide and gastr in. Recent findings support the hypothesis that an increase in circula ting motilin initiates the MMC at gastric level which, in turn, produc es the release of somatostatin. These hormones at least in dogs, may b e responsible for the aboral migration of MMC from the duodenum to the ileum and for the cycling rhythm by affecting blood levels of motilin and/or pancreatic polypeptide. The patterns of digestive motility may be adjusted pharmacologically and numerous agents are able to modify digestive motility in carnivorous. The authors described the nature of the motor effects of main pharmacologic agents used in humans for the treatment of the irritable bowel syndrome. However, in most cases, th e motor effects of these agents are specific, depending upon to experi mental protocol and route of administration but also from the digestiv e segment studied.