Electroacupuncture at acupoint ST 37(Shangjuxu) improves function of the enteric nervous system in a novel mouse constipation model

Abstract

BackgroundElectroacupuncture (EA) at acupoint ST 37 (Shangjuxu) has been used to alleviate gastrointestinal symptoms and improve gastrointestinal motility. However, the mechanisms by which EA affects the enteric nervous system (ENS) have scarcely been investigated. In this study, we investigated whether EA could improve ENS function.MethodsA constipation model was established by gastric instillation of ice-cold saline daily for 14 days. The constipated mice were divided into two groups: the model group, which was not treated, and the EA group, which received EA at ST 37 at a frequency of 2–15 HZ and an amplitude of 1 mA for 15 min a day for 3 days. A further six mice were included as a non-constipated control group. After EA treatment, intestinal propulsion and defecation time were measured. Additionally, in jejunum, ileum and proximal colon myenteric plexus, the expressions of PGP9.5 and nNOS were measured by immunohistochemistry.ResultsThe EA group demonstrated significant improvements in carbon propulsion rates and defecation time compared to model group (P < 0.05). In addition, after EA, the PGP9.5 and nNOS expression in jejunum, ileum and proximal colonic myenteric plexus was back to normal levels.ConclusionThis study suggests that EA stimulation at ST 37 is capable of ameliorating intestinal motility dysfunction, and can partly restore enteric neuron function. The ENS can participate in changes in intestinal motility by affecting inhibitory neurons.

Transcutaneous Electrical Acupuncture Stimulation (TEAS) for gastrointestinal dysfunction in adults undergoing abdominal surgery: study protocol for a prospective randomized controlled trial

“…Similarly, it has been reported by Iwa [17] et al that the application of EA in rats with conscious free movement may promote distal colon movement and accelerate colon transport through the sacral efferent parasympathetic pathway. EA may help repair damage to the GI barrier by regulating the neuroendocrine immune system and fighting inflammation [18] . EA stimulation of Zusanli and other acupoints can play a protective role in intestinal injury and mucosal barrier dysfunction of rats with blood loss by activating cholinergic anti-inflammatory pathways and intestinal glial cells (known to secrete epidermal growth factor, thereby increasing the recovery rate of epithelial cells) [19][20][21] .…”

TEAS treatment improves gastrointestinal function after abdominal surgery: study protocol for a prospective randomized controlled trial

“…The damage to the mucosal barrier is mainly caused by mucosal ischemia/reperfusion injury, inflammatory reactions, excessive gastric acid secretion and bacterial infection [22,23] . Electroacupuncture may help repair damage to the GI barrier by regulating the neuroendocrine immune system and fighting inflammation [24] . Electroacupuncture stimulation of Zusanli and other acupoints can play a protective role in intestinal injury and mucosal barrier dysfunction of rats with blood loss by activating cholinergic anti-inflammatory pathways and intestinal glial cells (known to secrete epidermal growth factor, thereby increasing the recovery rate of epithelial cells) [25][26][27] .…”

Electro‐acupuncture at ST37 and ST25 induce different effects on colonic motility via the enteric nervous system by affecting excitatory and inhibitory neurons

“…Constipation was induced by gastric instillation of 0‐4°C normal saline at a dose of 0.2 mL/mouse; the dose was then increased by 0.05 mL/mouse every 5 days. The gastric instillation was performed once daily for 14 consecutive days . Control mice were raised normally.…”

“…The gastric instillation was performed once daily for 14 consecutive days. 22,23 Control mice were raised normally. Constipated mice were selected from the model group according to changes in the size (see Figure 3) and weight of their feces…”

“…19 Many previous studies have confirmed that persistent stimulation with 0-4°C water can lead to gastrointestinal disorders, for instance, inhibition of jejunal and colonic movement. 20,21 Therefore, in this study, we created a mouse model of constipation that was induced by persistent stimulation with 0-4°C saline, 22,23 in order to examine the ENS mechanisms involved in the effects of EA at ST 37 and ST 25.…”