Vagal Nerve Regulation Is Essential for the Increase in Gastric Motility in Response to Mild Exercise

Abstract

It has been shown that mild to moderate exercise can accelerate gastric emptying in humans. However, understanding of the underlying mechanism is hampered by the lack of appropriate animal models. To investigate the effects of mild exercise on gastric motility, we developed an animal model, in which strain gauge transducers were surgically planted on the antral surfaces of female Sprague-Dawley rats. We continuously recorded the contractions of gastric circular muscle in unrestrained conscious rats, divided into four groups: sham-operated exercise, sham-operated sedentary, vagotomized exercise, and vagotomized sedentary. The rats were trained for 3 weeks, and gastric motility was monitored before and after exercise. Although exercise accelerates gastric antral contraction in sham-operated rats, this effect was absent in the vagotomized exercise group, indicating the involvement of the vagal nerve in the exercise-mediated increase in gastric motility. Among the four groups, daily food intake was highest in the sham-operated exercise group. In contrast, the vagotomized exercise group exhibited the smallest body weight gain. Severe gastric retention was observed in vagotomized rats, suggesting a role of the vagal nerve in facilitating food movement and digestion in the stomach. Moreover, at the end of the 3-week exercise, there were no differences in plasma levels of growth hormone, peptid YY, and ghrelin among the four groups. These results indicate that in response to a mild physical exercise challenge, the vagal nerve stimulates gastric motility and enhances the ability of the stomach to process food. Our findings highlight the significance of neuronal control of stomach function.

Acute Exercise and Gastric Emptying: A Meta-Analysis and Implications for Appetite Control

“…The relative dominance of sympathetic/parasympathetic activity is also influenced by exercise conditions [91]. During moderate intensity exercise, the vagal nerve appears to have a critical role in accelerating GE [30]. In addition, more powerful and stable gastric myoelectrical activity following moderate exercise could contribute to a faster GE [86,92].…”

“…In contrast, peptide YY and glucagon-like peptide 1 act as satiety signals and to inhibit GE [28]. In addition to hormonal influences, mechanical or neural factors such as the relative dominance of parasympathetic or sympathetic tone may contribute to variable GE responses to exercise [29,30].…”

Inhibitory effect ofSuaeda asparagoides(Miq.) extract on the motility of rat gastric antrum is mediated by β-adrenoceptor

“…Stimulating gastric motility agents also enhances gastric emptying [19-21]. On the other hand, higher concentrations SAWF may have a beneficial effect on symptoms associated with rapid gastric emptying.…”

Can natural ways to stimulate the vagus nerve improve seizure control?

“…This effect is thought to result from stimulating the VN, as the effect from exercise is abolished after vagotomy [52]. Studies have shown that cardiac vagal tone as assessed with HRV is increased in athletes compared to sedentary controls [53].…”