Effect of intraperitoneally injected dexmedetomidine on abdominal adhesions in rats and the role of cholinergic anti-inflammatory pathway / 中华麻醉学杂志

ABSTRACT

Objective@#To evaluate the effect of intraperitoneally injected dexmedetomidine on abdominal adhesions in rats and the role of cholinergic anti-inflammatory pathway.@*Methods@#Forty clean-grade healthy adult male Sprague-Dawley rats, weighing 220-250 g, were divided into 4 groups (n = 10 each) using a random number table method: sham operation group (Sham group), abdominal adhesion group (AA group), dexmedetomidine group (DEX group) and dexmedetomidine plus methyllycaconitine group (DEX-M group). The rat model of abdominal adhesions was established by cecal friction method.In Sham group, abdominal cavity was only opened and then sutured.Normal saline 2 ml was injected into the abdominal cavity and tail vein in group AA.In DEX and DEX-M groups, normal saline 2 ml and α7 nicotinic acetylcholine receptor antagonist methyllycaconitine 2.4 μg/g (dissolved in 2 ml normal saline) were injected, respectively, and dexmedetomidine 10 μg/kg (dissolved in 2 ml normal saline) was intraperitoneally injected at the same time.The abdominal incision was opened under anesthesia at 7 days after establishing the model to observe the formation of abdominal adhesion, Phillips method was used for scoring, and enzyme-linked immunosorbent assay was used to determine the transforming growth factor-beta1 (TGF-β1) concentrations in ascites and tumor necrosis factor-alpha (TNF-α) concentrations in serum.The rats were then sacrificed, and the caecum tissue and its contralateral peritoneum and adhesion fibrous strips were obtained for examination of the pathological changes with a light microscope.@*Results@#Compared with group Sham, the abdominal adhesion score and serum TNF-α concentrations were significantly increased in AA and DEX-M groups, and the TGF-β1 concentration in ascites was significantly increased in AA, DEX and DEX-M groups (P<0.05). Compared with group AA, the serum TNF-α concentrations and TGF-β1 concentration in ascites were significantly decreased in group DEX-M, and the abdominal adhesion score was significantly decreased (P<0.05), and the pathological changes of caecum tissue, contralateral peritoneum and adhesion fibrous strips were significantly attenuated in group DEX.Compared with group DEX-M, the serum TNF-α concentrations were significantly increased (P<0.05), no significant change was found in TGF-β1 concentration in ascites (P>0.05), and the pathological changes of caecum tissue, contralateral peritoneum and adhesion fibrous strips were accentuated in group DEX.@*Conclusion@#Intraperitoneally injected dexmedetomidine can mitigate abdominal adhesions, and the mechanism is related to activating cholinergic anti-inflammatory pathway and reducing systemic inflammatory response in rats.