Characteristics of Intestinal Myoelectrical and Motor Activities in Diet-Induced Obese Rats: Obesity and Motility

Abstract

Background: Gastrointestinal motility has been reported to be altered in obesity. However, it is unknown whether intestinal myoelectrical activity (IMA) is also changed in obesity.

Aims: The aim of this study was to characterize intestinal myoelectrical and motility activities in the fasting state, during feeding, and postprandial state after various test meals in diet-induced obese (DIO) rats in comparison with regular rats.

Methods: IMA was recorded in the fasting, feeding, and postprandial states in DIO and regular rats. Regular laboratory chow, high-fat solid food, and high-fat liquid food were used to test IMA responses to different meals.

Results: (1) The intestinal slow waves in the DIO rats were not different from those in normal rats in the fasting or postprandial state. Neither intestinal transit nor the number of intestinal contractions per minute was altered in DIO rats although gastric emptying was accelerated. (2) Both DIO rats and normal rats showed altered IMA during the first minute of feeding (cephalic stimulation). (3) The intestinal slow waves in both DIO rats and regular rats were impaired slightly but significantly after intake of a high-fat meal.

Conclusions: Our study demonstrates that intestinal myoelectrical activity is not altered in DIO rats and its postprandial responses to various meals are not altered either. High-fat meals induce intestinal dysrhythmia but do not have a chronic impact on intestinal slow waves in DIO rats.

Keywords: Gastric emptying; Gastrointestinal motility; Gastrointestinal transit; Intestines; Obesity.