The Protective Effct Of Thyroid Hormone On Function Of Intestinal Mucosa Barrier In Rats With Acute Hepatic Failure

Objective:To investigate the injury of intestinal mucosa barrier,the metabolic abnormalities of thyroid hormone(TH),and the protective effect of exogenous thyroid hormone(TH) on intestinal mucosa barrier in rats with acute hepatic failure.Methods:Thirty-four SD rats were randomly divided into three groups:â… Sham group(SO group),N=10;â…¡Acute hepatic failure group(AHF group), N=12;â…¢AHF treated with thyroid hormone(AHF+TH group),N=12.The AHF Rat model(â…¡andâ…¢groups) was created by repeated treatment of thioacetamide(TAA), 400mg/kg body weight(saline preparation 40mg/ml),by intraperitoneal injections at 0 and 24 hours.The rats in groupâ…¢(AHF+TH group) were treated with three intraperitoneal thyroid hormome(TH) injections(15mg/kg) at-30 min,18 hours and 36 hours post TAA treaements.All rats were slaughtered at 48 hours after the initial TAA intraperitoneal injection,and underwent serum FT₃,FT₄,TSH,rT₃,endotoxin, TB,and ALT level measurements.The levels of diamine oxidase(DAO) and ICAM-1 expression in the intestine were measured.The bacteria in ileum and mesenteric lymph nodes were also cultured to observe the structural integrity of the intestinal mucosa.Results:1) Groupâ…¡(AHF group) andâ…¢(AHF+TH) were compared to the Sham group respectively.We found that the serum levels of FT₃,FT₄ and the activities of DAO were decreased(p＜0.01),whereas the serum levels of rT₃,TB,AST,ALT,endotoxin and ICAM-1 expressions in the intestine were increased(p＜0.01).The migration of Enterobacteriaceae and enterococci to the mesenteric lymph nodes were increased (p＜0.01).In contrast,the migration of lactobacillus and bifidobacteria to the same location were decreased(p＜0.01).As a result,this disrupted the balance of bacterial composition in the intestine.2) When groupâ…¢(AHF+TH group) was compared to groupâ…¡(AHF),we found that the serum level of FT₃,FT₄ and the activities of DAO in the intestine were increased(p＜0.01/0.05) after thyroid hormone treatment in groupâ…¢.In contrast,the serum level of rT₃,TB,ALT,AST were decreased(p＜0.01/0.05).The number of intestinal Enterobacteriaceae and enterococci were decreased(p＜0.05),whereas the number of lactobacillus and bifidobacteria were increased in the intestine.And the migration rate of bacteria to the mesenteric lymph nodes,endotoxin and ICAM-1 expressions in the intestine were decreased,although not significantly(p＞0.05). This showed the injury of intestinal mucosa barrier was lessened(p＜0.05)Conclusion:Follow with the injure of intestinal mucosa barrier of acute hepatic failure,the level of FT₃,FT₄ and the activities of diamine oxidase were degraded,and the level of rT₃,the shifting rate of bacterium,endotoxin were increased.The supplement of exogenous thyroid hormone(TH) can protect intestinal mucosa barrier and the function of liver,and alleviate the injure of intestinal mucosa barrier in rats with acute hepatic failure.