Study Of Different Ratios Of N-6/n-3 PUFAs On Occurrence Of Chronic Reflux Esophagitis And Relating Mechanism

Objective:1. To establish the rat model of chronic reflux esophagitis(RE) with delayed gastric emptying and pyloric obstruction.2. To observe the effect of different level of n-6/n-3 polyunsaturated fatty acids(PUFAs) on the chronic RE.3. To explore the mechanism of different level of n-6/n-3 PUFAs in the treating of chronic reflux esophagitis.Methods:1. The rat model with chronic reflux esophagitis was established by restricting of the pyloric expansion and ligating of the gastric fundus. All 45 rats were divided into 3 groups equally according to the diameters including 3.6mm, 4.0mm and 4.4mm. In addition, control group contained 15 rats were established. The esophagitis specimens were harvested for morphological studies by HE staining after 2 weeks, and the incidence of esophagitis in every group were collected.2. 60 esophagitis rats were randomly allocated into 4 groups according to the ratio of n-6/n-3 polyunsaturated fatty acids in fodder including 12:1,10:1,5:1 and 1:1. In addition, control group contained 15 rats were established. Two weeks later, all rats were sacrificed and the esophagitis specimens were taken. The pathological changes were observed by HE staining, the expression of inflammatory cytokines including IL-1β,IL-6,IL-8,TNFα m RNA and protein were detected by Real-time PCR and Western blot, respectively.3.The expression of key target protein including PI3 K, p-Akt and NF-κB in PI3K/Akt-NF-κB signaling pathway in the esophagitis specimens were detected by Real-time PCR and Western blot.Results:1. The survival ratio in 3.6mm group, 4.0mm group, 4.4mm group and control groups was 26.7%, 80%, 86.7% and 100%, respectively. And the incidence of the reflux esophagitis was 0, 100%, 83.3% and 21.4%, respectively. Compared with that in 4.4mm group, the survival ratio in 4.0mm group was lower(P<0.05), but the incidence of esophagitis was no difference(P>0.05).2. The expression of IL-1β,IL-6,IL-8 and TNF-α in experimental groups was declined with the decreasing of the n-6/n-3 PUFAs ratio in dietary, respectively. And the expression in 1:1 group were lowest(P<0.05).3. The expression of PI3K、Akt、p-Akt and NF-κB in experimental groups was declined with the decreasing of the n-6/n-3 ratio in dietary, respectively. And the expression in 1:1 group were lowest in all groups(P<0.05).Conclusions:1. The rat model of chronic reflux esophagitis was established by restricting of the pyloric expansion and ligating of the gastric fundus. And compared with the others, the rats of which pyloric diameter was 4.0 mm have a higher long-term survival ratio and incidence of RE. This is a simplified and standardized model.2. The expression of inflammatory cytokines in esphoageal mucosa of the RE rats was declined with the decreasing of the n3 PUFAs ratio in dietary, and that could mitigate the esophageal mucosal inflammation.3. N-3 PUFAs could mitigate the inflammatory response in esphoageal mucosa of the RE rats according to inhibiting the target proteins of PI3K/Akt-NF-κB signaling pathway.