Role of mitogen-activated protein kinases in the regulation of paraventricular nucleus to gastric ischemia-reperfusion injuries.
BACKGROUND
We investigated the role in electrical stimulations of paraventricular nucleus (PVN) on gastric mucosal cells and the activity of mitogen-activated protein kinases (MAPKs) family members induced by gastric ischemia-reperfusion (GI-R). And we elucidated the molecular mechanisms of the protection of PVN from GI-R injuries.


METHODS
Sprague-Dawley rats were divided randomly into 4 groups: Group I, the sham-operated GI-R control group; Group II, the sham-operated electrical stimulations to PVN + sham-operated GI-R control group; Group III, the GI-R group; and Group IV, the electrical stimulations to PVN + GI-R group. In all of the experiments, the PVN was stimulated prior to the induction of GI-R. The GI-R model was established by clamping the celiac artery for 30 minutes to induce ischemia and then was released to allow reperfusion for 30 minutes, 1 hour, 3 hours and 6 hours, respectively. The gastric mucosal cellular apoptosis, proliferation, and the expression and activity of MAPKs protein were observed by immunohistochemistry and Western blotting, respectively.


RESULTS
Compared with the GI-R group, the application of electrical stimulations in the PVN significantly depressed gastric mucosal cellular apoptosis and enhanced gastric mucosal cellular proliferation following the 30-minute, 1-hour and 3-hour intervals of reperfusion; it also promoted the activation of p-ERK during the early phase of reperfusion but inhibited the activation of p-JNK1/2 and p-p38 following the 30-minute, 1-hour and 3-hour intervals of reperfusion.


CONCLUSIONS
The protection of PVN against GI-R injuries may attribute to the inhibition of apoptosis and the promotion of the proliferation of gastric mucosal cells during GI-R. This protective effect is mediated by activating the ERK pathway and depressing the JNK, p38 MAPK pathways of the gastric mucosal cells.
Li
Li
L
Department of Pathophysiology, Xuzhou Medical College, Xuzhou 221002, China.
Zhang
Yong-Mei
YM
Qiao
Wei-Li
WL
Zhang
Jian-Fu
JF
Wang
Lin
L
D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D004558:Electric Stimulation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000502:physiology; D005753:Gastric Mucosa / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology; D048031:JNK Mitogen-Activated Protein Kinases / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases