Expression of epoxygenases belonging to CYP2 family in rat myocardial ischemia/reperfusion injury in vivo.
OBJECTIVE
To elucidate the expression of epoxygenases belonging to cytochrome P-450 mono-oxygenases (CYP2) family in rat ischemic myocardium at varying reperfusion periods, and the effect of epoxygenase inhibition on the post-ischemic heart.


METHODS
The current study was conducted in the Department of Pharmacology, Medical College of Wuhan University, China, between September 2004 and June 2005. Rats were subjected to 40 minutes of myocardial ischemia, followed by 0, 15, 60, and 180 minutes of reperfusion. Superoxide generation was assayed by confocal microscopy, CYP2B1/2, 2C6, 2E1, 2J3 gene expressions were determined by reverse transcriptase polymerase chain reaction. Fourteen, 15-dihydroxyeicosatrienoic acid (DHET) concentration was measured by enzyme-linked immunosorbent assay. The effects of the CYP epoxygenase inhibitor N-methylsulphonyl-6-(2-propargyloxyphenyl) hexanamide (MS-PPOH) on myocardial damage and superoxide generation caused by 60 minutes of reperfusion were also evaluated.


RESULTS
During myocardial ischemia/reperfusion, CYP2C6 and 2J3 mRNA expression were up-regulated with the peak level at 15 minutes of reperfusion; CYP2E1 gene expression decreased in a time dependent manner and reached the minimum level at 180 minutes of post-ischemia. Meanwhile, no obvious variations of CYP2B1/2 gene expression were detected during different reperfusion periods. Fourteen, 15-DHET significantly increased during reperfusion in ischemic hearts. The MS-PPOH pretreatment (15 mg/kg) effectively reduced myocardial damage and superoxide production.


CONCLUSIONS
There are changes in gene expression of individual isozymes and an elevation of CYP epoxygenase activity involved in myocardial reperfusion injury in vivo. Epoxygenase inhibition plays a protective role in cardiac post-ischemic damage.
Ao
Ying
Y
Department of Pharmacology, Medical College of Wuhan University, Wuhan, China.
Peng
Ren-Xiu
RX
Yang
Jing
J
Wang
Bing-Hua
BH
Falck
John R
JR
Dan
Hong
H
Liu
Ying-Hui
YH
D000577:Amides / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D017202:Myocardial Ischemia / Q000201:enzymology*; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000201:enzymology* / Q000517:prevention & control; D010088:Oxidoreductases / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism; D015854:Up-Regulation
D000577:Amides; C121756:N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide; D013481:Superoxides; D008315:Malondialdehyde; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D007770:L-Lactate Dehydrogenase; C111866:CYP2B12 protein, rat; D003402:Creatine Kinase