CCK-8 inhibits expression of TNF-alpha in the spleen of endotoxic shock rats and signal transduction mechanism of p38 MAPK.
OBJECTIVE
To study the effect of sulfated cholecystokinin-octapeptide (CCK-8) on systemic hypotension, gene and protein expression of TNF-alpha in the spleen of lipopolysaccharide (LPS)-induced endotoxic shock (ES) rats, and further investigate the signal transduction mechanism of p38 mitogen-activated protein kinase (MAPK).


METHODS
The changes of blood pressure were observed using physiological record instrument in the four groups of rats: LPS (8 mg x kg(-1), iv), CCK-8 (40 microg x kg(-1), iv) pretreatment 10 min before LPS (8 mg x kg(-1)), CCK-8 (40 microg x kg(-1), iv) or normal saline (control) group. The content of TNF-alpha in the spleen was assayed 2 h after LPS administration using ELISA kit and the expression of TNF-alpha mRNA was examined 30 min, 2 h and 6 h after LPS administration by reverse transcribed polymerase chain reaction (RT-PCR). Activation of p38 MAPK was detected with Western blot 30 min after LPS administration.


RESULTS
CCK-8 reversed LPS-induced decrease of mean arterial pressure (MAP) in rats. The content of TNF-alpha in the spleen was (282+/-30) ng x L(-1) in control group, while it increased to (941+/-149) ng x L(-1) in LPS group, P<0.01. CCK-8 significantly inhibited the LPS-induced increase of TNF-alpha content in spleen. It decreased to (462 +/-87) ng x L(-1) in CCK-8+LPS group, P<0.01. The expression of TNF-alpha mRNA 30 min and 2 h after treatment was stronger in LPS group, while it was lowered after CCK-8 pretreatment. The p38 MAPK expression increased significantly in LPS group (5.84 times of control) and CCK-8 increased the activation of p38 MAPK in ES rats (10.74 times of control).


CONCLUSIONS
CCK-8 reverses the decrease of MAP in ES rats and has inhibitory effect on the gene and protein expression of TNF-alpha in spleen, and p38 MAPK may be involved in its signal transduction mechanisms.
Meng
Ai-Hong
AH
Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China.
Ling
Yi-Ling
YL
Zhang
Xiao-Peng
XP
Zhao
Xiao-Yun
XY
Zhang
Jun-Lan
JL
D000818:Animals; D015153:Blotting, Western; D019446:Endotoxemia / Q000139:chemically induced / Q000503:physiopathology*; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects; D008070:Lipopolysaccharides; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012844:Sincalide / Q000494:pharmacology*; D013154:Spleen / Q000201:enzymology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D048051:p38 Mitogen-Activated Protein Kinases
D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D012844:Sincalide