TY - JOUR
T1 - Effects of the selective EET antagonist, 14,15-EEZE, on cardioprotection produced by exogenous or endogenous EETs in the canine heart
AU - Gross, Garrett J.
AU - Gauthier, Kathryn M.
AU - Moore, Jeannine
AU - Falck, J R
AU - Hammock, Bruce D.
AU - Campbell, William B.
AU - Nithipatikom, Kasem
PY - 2008/6
Y1 - 2008/6
N2 - Previously, we demonstrated (17) that 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) produce marked reductions in myocardial infarct size. Although it is assumed that this cardioprotective effect of the EETs is due to a specific interaction with a membrane-bound receptor, no evidence has indicated that novel EET antagonists selectively block the EET actions in dogs. Our goals were to investigate the effects of 11,12- and 14,15-EET, the soluble epoxide hydrolase inhibitor, 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA), and the putative selective EET antagonist, 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE), on infarct size of barbital anesthetized dogs subjected to 60 min of coronary artery occlusion and 3 h of reperfusion. Furthermore, the effect of 14,15-EEZE on the cardioprotective actions of the selective mitochondrial ATP-sensitive potassium channel opener diazoxide was investigated. Both 11,12- and 14,15-EET markedly reduced infarct size [expressed as a percentage of the area at risk (IS/AAR)] from 21.8 ± 1.6% (vehicle) to 8.7 ± 2.2 and 9.4 ± 1.3%, respectively. Similarly, AUDA significantly reduced IS/AAR from 21.8 ± 1.6 to 14.4 ± 1.2% (low dose) and 9.4 ± 1.8% (high dose), respectively. Interestingly, the combination of the low dose of AUDA with 14,15-EET reduced IS/AAR to 5.8 ± 1.6% (P < 0.05), further than either drug alone. Diazoxide also reduced IS/AAR significantly (10.2 ± 1.9%). In contrast, 14,15-EEZE had no effect on IS/AAR by itself (21.0 ± 3.6%), but completely abolished the effect of 11,12-EET (17.8 ± 1.4%) and 14,15-EET (19.2 ± 2.4%) and AUDA (19.3 ± 1.6%), but not that of diazoxide (10.4 ± 1.4%). These results suggest that activation of the EET pathway, acting on a putative receptor, by exogenous EETs or indirectly by blocking EET metabolism, produced marked cardioprotection, and the combination of these two approaches resulted in a synergistic effect. These data also suggest that 14,15-EEZE is not blocking the mitochondrial ATP-sensitive potassium channel as a mechanism for antagonizing the cardioprotective effects of the EETs.
AB - Previously, we demonstrated (17) that 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) produce marked reductions in myocardial infarct size. Although it is assumed that this cardioprotective effect of the EETs is due to a specific interaction with a membrane-bound receptor, no evidence has indicated that novel EET antagonists selectively block the EET actions in dogs. Our goals were to investigate the effects of 11,12- and 14,15-EET, the soluble epoxide hydrolase inhibitor, 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA), and the putative selective EET antagonist, 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE), on infarct size of barbital anesthetized dogs subjected to 60 min of coronary artery occlusion and 3 h of reperfusion. Furthermore, the effect of 14,15-EEZE on the cardioprotective actions of the selective mitochondrial ATP-sensitive potassium channel opener diazoxide was investigated. Both 11,12- and 14,15-EET markedly reduced infarct size [expressed as a percentage of the area at risk (IS/AAR)] from 21.8 ± 1.6% (vehicle) to 8.7 ± 2.2 and 9.4 ± 1.3%, respectively. Similarly, AUDA significantly reduced IS/AAR from 21.8 ± 1.6 to 14.4 ± 1.2% (low dose) and 9.4 ± 1.8% (high dose), respectively. Interestingly, the combination of the low dose of AUDA with 14,15-EET reduced IS/AAR to 5.8 ± 1.6% (P < 0.05), further than either drug alone. Diazoxide also reduced IS/AAR significantly (10.2 ± 1.9%). In contrast, 14,15-EEZE had no effect on IS/AAR by itself (21.0 ± 3.6%), but completely abolished the effect of 11,12-EET (17.8 ± 1.4%) and 14,15-EET (19.2 ± 2.4%) and AUDA (19.3 ± 1.6%), but not that of diazoxide (10.4 ± 1.4%). These results suggest that activation of the EET pathway, acting on a putative receptor, by exogenous EETs or indirectly by blocking EET metabolism, produced marked cardioprotection, and the combination of these two approaches resulted in a synergistic effect. These data also suggest that 14,15-EEZE is not blocking the mitochondrial ATP-sensitive potassium channel as a mechanism for antagonizing the cardioprotective effects of the EETs.
KW - ATP-sensitive potassium channel opener
KW - Cytochrome P-450 epoxygenase
KW - Epoxyeicosatrienoic acids
KW - Soluble epoxide hydrolase
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U2 - 10.1152/ajpheart.00186.2008
DO - 10.1152/ajpheart.00186.2008
M3 - Article
C2 - 18441205
AN - SCOPUS:49249116223
SN - 0363-6135
VL - 294
SP - H2838-H2844
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 6
ER -