Protective Effects Of Sufentanil Pretreatment Against Acute Gastric Mucosal Lesion Induced By WIRS In Rats And Its Relationship With TRPV1/ASIC3

Background Acute gastric mucosal lesion(AGML) was a severe complication in clinic practice, it is a pathopysiological course of disequilibrium between gastric mucosa protection agent and invasion agent induced by many factors. But its mechanism and pathophysiology were not yet completely understood. Under many conditions such as shock, sepsis, hypoperfusion and many other disease, acidosis of gastrointestinal tract could be induced. The decrease of pH in gastrointestinal tract has already been a mark of many pathophysiological process, adequate acid-sensitive plays an important role in the maintenance of the internal environment of GI, while unadequate acid-sensitive could contribute to the genesis of inflammation and mucosa ulcer.Sufentail is anμ- opoid receptor agonist widely used in clinical anesthesia and analgesia. We have already investigated and discovered its protective effect against AMGL induced by WIRS, but its mechanism still need to be explored. Transient receptor potential vanilloid-1 (TRPV1) and acid-sensitive ion channel-3 (ASIC3) are both acid sensitive ion channels, being coexistence in DRG neurons, play a great role in the maintenance of the internal environment of GI.,the Efferent-like roles of TRPV1 is the most important endogenous protection mechanism of gastric. TRPV1/ASIC3 are both inociception Ca2+ selective ion channel, the expression of TRPV1/ASIC3 could be up-regulated in the infla-hypersensitivity reactions. Application ofμ-opoid receptor agonist in periphery way is effective in inhibiting infla-hypersensitivity reactions, so we suppose that opoids could regulate the expression or activity of TRPV1/ASIC3, but mechanism was not completely undersdood.Objection To obtain the evidence of coexistence ofμ-opoid receptor and TRPV1/ASIC3, to explain the effect of TRPV1/ASIC3 in AGML genesis mechanism, and to investigate the relationship betweenμ-opoid receptor and TRPV1/ASIC3, and its regulation mechanism.Method (1)TRPV1 andμ-opoid receptor were coexistence in gastricproject DRG neurons.Twelve healthy male Wistar rats were divided into 2 groups randomly, the nomal control group (Group NC) and WIRS group(Group WS). The coexistence expression ofμ-opoid receptor and TRPV1 in gastric project DRG neurons were detected by immunohistochemistry. (2)The protection effect of sufentainil prediction against acute gastric mucosal lesion induced by WIRS in rats and its relationship with TRPV1.Tirty-six Wistar rat were randomly assigned to 3 groups, including normal control group(Group NC), WRIS group(Group WS) and sufentanyl pretreatment group(Group SF). Gsatric mucosal lesion model was induced by water immersion and restraint stress (WRIS) in water temperature 20±1℃. To observe the mRNA and protein expression of TRPV1 in gastric project DRG neurons through RT-PCR and Western-Blot in rats; to determin the CGRP levels of gastric tissue through ELASA. (3)The protection effect of amiloride prediction against against acute gastric mucosal lesion induced by WIRS in rats Tirty healthy male Wistar rats were divided into 3 groups randomly,including Group NC (normal group), Group WS (WRIS stress group), Group AM (Amiloride preconditioning stress group), After 6h of WRIS, gastric tissues were excised and gastric leision index was observed and countered under the 10×anatomical microscope, the levels of MDA and SOD in gastric tissues were detected by colorimetric assay. (4)he protection effect of sufentainil prediction against acute gastric mucosal lesion induced by WIRS in rats and its relationship with ASIC3.Twenty-four Wistar rat were randomly assigned to 3 groups,including Group NC(normal group,n=6), Group WS (WRIS stress group, n=12, Group SF(sufentanil preconditioning stress group, n=6),the expression of ASIC3 was detected in gastric projected DRG neurons by immunohistochemistry. The mRNA expression of ASIC3 in DRG neurons was detected through real-time quantitive RT-PCR.Result (1)We investigated that TRPV1 andμ- opoid receptor were coexistence in gastricproject DRG neurons. (2)Compared with Group NC, the gastric mucosal lesion was severe in Group WS, and the level of TRPV1 protein of DRG neurons was significantly up regulated (F=315.168, P=0.000), also the level of CGRP in gastric mucosa increased sinificantly (F=33.142, P=0.006), while the expression of TRPV1mRNA had no difference (F=0.352, P=0.708); compared with group WS; the gastric mucosal lesion was relieved in group SF, the level of TRPV1 protein of DRG neurons increasd significantly (F=315.168, P=0.000) as well as the level of CGRP in gastric mucosa (F=33.142, P=0.000), while the expression of TRPV1mRNA did not change (P<0.05).(3)Compared with Group WS, Group AM attenuates gastric lesion degrees significantly (F=132.299, P=0.000)); Compared with Group WS, Group AM decreases concentration of MDA (F=29.469, P=0.000) and increases concentration of SOD significantly (F=36.395, P=0.000). (4)We discover the expression of ASIC3 in gastric projected DRG neurons, and the level of ASIC3mRNA increased significantly in group WS compared to group NC (F=26.295, P=0.004), while sufetanil could attenuates the up-regulation (F=26.295, P=0.023)Conclusion①TRPV1 andμ- opoid receptor contribute to the development mechanism of AMGL, and the two receptors have relationship in founction.②TRPV1 contribute to the mechanism of Sufentanil protection effect on AMGL, theμ-opoid receptor agonist can increase the expression of TRPV1, also theμ- opoid receptor agonist can activate TRPV1 to release CGRP to protect the gastric mucosa.③ASIC3 could contribute to the development mechanism of AMGL, blockade of ASIC3 could relieve the gastric damage of rat during WIRS.④The mechanism of Sufentanil protecting gastric mucosa might relate to inhibiting the expression of ASIC3.