title: Differential expression of Bcl-2 and Bax during gastric ischemia-reperfusion of rats.
abstract: OBJECTIVE
  To investigate expression of Bcl-2 and Bax in gastric ischemia-reperfusion (GI-R) and involvement of extracellular signal-regulated kinase (ERK) 1/2 activation.
  
  
  METHODS
  The GI-R model was established by ligature of the celiac artery for 30 min and reperfusion in Sprague-Dawley rats. Rats were assigned to groups in accordance with their evaluation period: control, 0, 0.5, 1, 3, 6, 24, 48, and 72 h. Expression and distribution of Bcl-2 and Bax proteins were analyzed by immunohistochemistry and western blotting in gastric tissue samples after sacrifice.
  
  
  RESULTS
  Compared with controls, the percentage of positive cells and protein levels of Bcl-2 decreased in the early phases of reperfusion, reached its minimum at 1 h (P < 0.05); it then increased, reaching its peak at 24 h of reperfusion (P < 0.05). The pattern of Bax expression was opposite to that of Bcl-2. Bax expression increased after reperfusion, with its peak at 1 h of reperfusion (P < 0.05), and then it decreased gradually to a minimum at 24 h after reperfusion (P < 0.05). On the other hand, inhibition of activation of ERK1/2 induced by PD98059, a specific upstream MEK inhibitor, had significant effects on Bcl-2 and Bax in GI-R. Compared with GI-R treatment only at 3 h of reperfusion, PD98059 reduced the number of Bcl-2 positive cells (0.58% of R3h group, P < 0.05) and Bcl-2 protein level (74% of R3h group, P < 0.05) but increased the number of Bax-positive cells (1.33-fold vs R3h group, P < 0.05) and Bax protein level (1.35-fold of R3h group, P < 0.05).
  
  
  CONCLUSIONS
  These results indicated that the Bcl-2 and Bax played a pivotal role in the gastric mucosal I-R injury and repair by activation of ERK1/2.
authors.affiliation: Department of Physiology, Xuzhou Medical College, 84 West Huaihai Road, Xuzhou 221002, Jiangsu Province, China.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Qiao
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Shi
authors.forename: Jin-Xia
authors.initials: JX
authors.lastname: Wu
authors.forename: You-Jian
authors.initials: YJ
authors.lastname: Qi
authors.forename: Jian-Fu
authors.initials: JF
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.forename: Chang-Dong
authors.initials: CD
authors.lastname: Yan
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply* / Q000473:pathology* / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology* / Q000503:physiopathology*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D048049:Extracellular Signal-Regulated MAP Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one