T1332 Electroacupuncture Improves Impaired Gastric Accommodation and Vagal Activity in a Novel Rodent Model of Functional Dyspepsia

Abstract

Background and Aims: Acupuncture has been used for treating gastric motor dysfunctions. Recently, a rodent model of functional dyspepsia (FD) has been established by transient gastric irritation during the neonatal period, a time of known neuronal vulnerability to long term plasticity. The aim of this study was to investigate the effect of electroacupuncture (EA) on gastric accommodation and vagal activity in this rodent model. Methods: 10 days old male Sprague-Dawley rats received 0.2 ml 0.1% iodoacetamide (IA) in 2% sucrose daily by oral gavages for 6 days; controls received 2% sucrose for the same duration. Rats in both groups were then allowed to grow normally to adult age (8-11 weeks) at which point gastric accommodation and autonomic functions, and their responses to EA were measured. An electronic barostat was used to measure gastric accommodation. Autonomic functions were assessed by the spectral analysis of heart rate variability that was derived from the electrocardiogram signal. EA was delivered via ST-36 which is located at 5 mm lateral and lower from the anterior tubercle of the tibia in rats. Results: 1) Rats in IA group exhibited reduced gastric accommodation and vagal activity (P<0.05). Compared with the control group, gastric accommodation and vagal activity in IA group were decreased 58 ± 5% (0.16 ± 0.09 ml vs. 0.39 ± 0.18 ml, p=0.004) and 26 ± 2% (0.33 ± 0.09 vs. 0.45 ± 0.10, P0.03), respectively. 2) EA improved impaired gastric accommodation and vagal activity in rats with IA. In contrast to Sham EA-IA, gastric accommodation and vagal activity were increased 51 ± 3% (0.35 ± 0.15 vs. 0.17 ± 0.12 ml, P=0.02) and 27 ± 2% (0.48±0.09 vs. 0.35 ± 0.11, P=0.04), respectively. 3) No significant gastric pathology was seen in impaired accommodation adult rats compared to the controls. Conclusions: Acute mild gastric inflammation in the neonatal period results in reduced gastric accommodation and vagal activity that persists through adulthood. EA normalizes impaired accommodation, possibly by exciting vagal activity, and may have a great potential for treating gastric motor dysfunctions.