title: Emodin promoted pancreatic claudin-5 and occludin expression in experimental acute pancreatitis rats.
abstract: OBJECTIVE
  To investigate the effect of emodin on pancreatic claudin-5 and occludin expression, and pancreatic paracellular permeability in acute pancreatitis (AP).
  
  
  METHODS
  Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Emodin was injected via the external jugular vein 0 or 6 h after induction of AP. Rats from sham operation and AP groups were injected with normal saline at the same time. Samples of pancreas were obtained 6 or 12 h after drug administration. Pancreatic morphology was examined with hematoxylin and eosin staining. Pancreatic edema was estimated by measuring tissue water content. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 level were measured by enzyme-linked immunosorbent assay. Pancreatic paracellular permeability was assessed by tissue dye extravasation. Expression of pancreatic claudin-5 and occludin was examined by immunohistology, quantitative real-time reverse transcriptase polymerase chain reaction and western blotting.
  
  
  RESULTS
  Pancreatic TNF-α and IL-6 levels, wet/dry ratio, dye extravasation, and histological score were significantly elevated at 3, 6 and 12 h following sodium taurocholate infusion; treatment with emodin prevented these changes at all time points. Immunostaining of claudin-5 and occludin was detected in rat pancreas, which was distributed in pancreatic acinar cells, ductal cells and vascular endothelial cells, respectively. Sodium taurocholate infusion significantly decreased pancreatic claudin-5 and occludin mRNA and protein levels at 3, 6 and 12 h, and that could be promoted by intravenous administration of emodin at all time points.
  
  
  CONCLUSIONS
  These results demonstrate that emodin could promote pancreatic claudin-5 and occludin expression, and reduce pancreatic paracellular permeability.
authors.affiliation: Department of Gastroenterology and Hepatology, the Fourth Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui Province, China. xiaxm2000@hotmail.com
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Xia
authors.forename: Bang-Ku
authors.initials: BK
authors.lastname: Li
authors.forename: Shi-Mei
authors.initials: SM
authors.lastname: Xing
authors.forename: Hai-Ling
authors.initials: HL
authors.lastname: Ruan
mesh_terms: D000208:Acute Disease; D000818:Animals; D062507:Claudin-5; D057167:Claudins / Q000032:analysis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis; D004642:Emodin / Q000494:pharmacology*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D062793:Occludin; D010179:Pancreas / Q000737:chemistry / Q000187:drug effects* / Q000276:immunology; D010195:Pancreatitis / Q000378:metabolism*; D010539:Permeability; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D062507:Claudin-5; D057167:Claudins; C491510:Cldn5 protein, rat; D016207:Cytokines; D008565:Membrane Proteins; D062793:Occludin; C568987:Ocln protein, rat; D012333:RNA, Messenger; D004642:Emodin