A simple method to investigate the inhibitory effects of drugs on gastric emptying in the mouse in vivo

Introduction: The aim was to develop a simple method to study modification of gastric motility in the mouse in vivo. Methods: Mice were fed a hydrated diet in which the fluid content of standard laboratory chow was increased by adding water. Gastric emptying was assessed at specified times following a 1-h treatment period with orally administered pharmacological agents. Results: We demonstrated consistent and progressive gastric emptying over a 4-h period, stomach content being decreased from 7.52±0.90 at time zero to 2.80±0.25 mg/g body weight after 4 h. Results demonstrated typical effects of inhibitory agents (atropine and morphine) and showed inhibitory effects of three potassium channel opening agents, pinacidil, cromakalim, and SDZ PCO400: the residue remaining in the stomach was increased by 3.66±0.84, 6.56±1.35, and 5.68±1.33 mg/g body weight respectively 1 h after treatment with 10 mg/kg of these agents, compared to vehicle controls. Discussion: The inhibitory activity observed correlated well with previous studies on the effects of potassium channel opening agents on mouse gastrointestinal motility in vivo and in vitro. The present model may thus be of value in the pharmacological investigation of gastrointestinal motility owing to cost and convenience advantages, together with the possibility of its application to studies using transgenic animals.