An assessment of two gastric transport models currently used in safety pharmacology testing

Abstract

1 The potential effects of new drugs on the digestive system can be examined in a number of model systems of which intestinal motility in the mouse and/or gastric emptying in the rat are examples recommended for safety pharmacology evaluation. 2 Intestinal motility, assessed by the transit of carmine dye in the mouse and gastric motility, assessed by stomach weight in the rat, were examined using a range of clinical drugs or potent pharmacological agents known to affect gastrointestinal function. Assessment of both models in the guinea-pig was also evaluated. 3 Activity was demonstrated with codeine, diazepam, atropine and CCK-8 (all of which inhibited gastric function). However, neither model gave consistent and reliable results with the remaining reference compounds, namely metoclopramide, bethanechol, cisa-pride, deoxycholate, carbachol and domperidone. 4 In conclusion, this investigation questions the usefulness of simple models of gastrointestinal transport in the rodent as a means of detecting potential effects of a new drug on the digestive system. This finding should be of concern to the pharmaceutical industry as these simple models are routinely used as part of a regulatory safety pharmacology `package' of studies.