J Neurogastroenterol Motil.  2013 Oct;19(4):454-466.

Blunted Peripheral and Central Responses to Gastric Mechanical and Electrical Stimulations in Diet-induced Obese Rats

• Zhang J
• Sha W
• Zhu H
• Chen JD

Abstract

BACKGROUND/AIMS
The increase in the prevalence of obesity is attributed to increased food intake and decreased physical activity in addition to genetic factors. Altered gut functions have been reported in obese subjects, whereas, little is known on the possible alterations in brain-gut interactions in obesity. The aim of the study was to explore possible alterations in gastric myoelectrical activity, gastric emptying, autonomic functions and central neuronal responses to gastric stimulations in diet-induced obese rats.
METHODS
Gastric myoelectrical activity, gastric emptying and heart rate variability were recorded in lean and obese rats; extracellular neuronal activity in the ventromedial hypothalamus and its responses to gastric stimulations were also assessed.
RESULTS
(1) Gastric emptying was significantly accelerated but gastric myoelectrical activity was not altered in obese rats; (2) the normal autonomic responses to feeding were absent in obese rats, suggesting an impairment of postprandial modulation of autonomic functions; and (3) central neuronal responses to gastric stimulations (both balloon distention and electrical stimulation) were blunted in obese rats, suggesting impairment in the brain-gut interaction.
CONCLUSIONS
In diet-induced obese rats, gastric emptying is accelerated, postprandial modulations of autonomic functions is altered and central neuronal responses to gastric stimulations are attenuated. These alterations in peripheral, autonomic and brain-gut interactions may help better understand pathogenesis of obesity and develop novel therapeutic approaches for obesity.

Keyword

Autonomic function; Brain-gut interation; Central nervous system; Gastrointestinal motility; Obesity

MeSH Terms

Animals
Central Nervous System
Eating
Electric Stimulation*
Gastric Emptying
Gastrointestinal Motility
Heart Rate
Hypothalamus
Motor Activity
Obesity
Prevalence
Rats*