| Autor: |
Yadav VR; Department of Physiology and Pharmacology, College of Medicine, West Virginia University, Morgantown, WV, USA., Hong KL; Department of Pharmaceutical Sciences, Center for Basic and Translational Stroke Research, Health Science Center-North, School of Pharmacy, West Virginia University, Biomedical Research Building, 2nd floor, Room # 220, 1 Medical Center Drive, PO Box 9530, Morgantown, WV, 26506-9530, USA., Zeldin DC; Division of Intramural Research, NIEHS/NIH, Research Triangle Park, NC, USA., Nayeem MA; Department of Pharmaceutical Sciences, Center for Basic and Translational Stroke Research, Health Science Center-North, School of Pharmacy, West Virginia University, Biomedical Research Building, 2nd floor, Room # 220, 1 Medical Center Drive, PO Box 9530, Morgantown, WV, 26506-9530, USA. mnayeem@hsc.wvu.edu. |
| Abstrakt: |
Soluble epoxide hydrolase (sEH) converts epoxyeicosatrienoic acids that are endothelium-derived hyperpolarizing factors into less active dihydroxyeicosatrienoic acids. Previously, we reported a decrease in adenosine A 1 receptor (A 1 AR) protein levels in sEH knockout (sEH -/- ) and an increase in sEH and A 1 AR protein levels in A 2A AR -/- mice. Additionally, K ATP channels are involved in adenosine receptor (AR)-dependent vascular relaxation. Thus, we hypothesize that a potential relationship may exist among sEH over-expression, A 1 AR upregulation, inactivation of K ATP channels, and increased in vascular tone. We performed DMT myograph muscle tension measurements and western blot analysis in isolated mouse mesenteric arteries (MAs) from wild-type (WT) and endothelial over-expression of sEH (Tie2-sEH Tr) mice. Our data revealed that NECA (a non-selective adenosine receptors agonist)-induced relaxation was significantly reduced in Tie2-sEH Tr mice, and CCPA (A 1 AR agonist)-induced contraction was increased in Tie2-sEH Tr mice. A 1 AR-dependent contraction in Tie2-sEH Tr mice was significantly attenuated by pharmacological inhibition of CYP4A (HET0016, 10 µM), PKCα (GO6976, 1 µM), and ERK1/2 (PD58059, 1 µM). Our western blot analysis revealed significantly higher basal protein expression of CYP4A, A 1 AR, and reduced p-ERK in MAs of Tie2-sEH Tr mice. Notably, pinacidil (K ATP channel opener)-induced relaxation was also significantly reduced in MAs of Tie2-sEH Tr mice. Furthermore, K ATP channel-dependent relaxation in MAs was enhanced by inhibition of PKCα and ERK1/2 in WT but not Tie2-sEH Tr mice. In conclusion, our data suggest that over-expression of sEH enhances A 1 AR-dependent contraction and reduces K ATP channel-dependent relaxation in MAs. These results suggest a possible interaction between sEH, A 1 AR, and K ATP channels in regulating vascular tone. |
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