Objective: To investigate the mechanism of enhanced large conductance calcium-activated potassium channel currents (BK) in coronary smooth muscle cells (SMCs) by docosahexaenoic acid (DHA).
Methods: Coronary SMCs were isolated by enzyme digestion. Potassium channels in coronary SMCs were identified by applications of different potassium blockers. Effects of DHA and its metabolite 16, 17-epoxydocosapentaenoic acid (16, 17-EDP) on BK channels in the absence and presence of cytochrome P450 epoxygenase inhibitor SKF525A were studied by patch clamp in whole-cell configuration.
Results: BK channels were widely distributed in SMCs, and BK currents in normal SMCs accounted for (64.2 ± 2.7)% of total potassium currents (n = 20). DHA could activate BK channels, and its 50% effective concentration (EC(50)) was (0.23 ± 0.03) µmol/L, however, the effect of DHA on BK channels was abolished after SMCs were incubated with cytochrome P450 epoxygenase inhibitor SKF525A. 16, 17-EDP, a metabolite of DHA, could reproduce the effects of DHA on BK channels, and its EC(50) was (19.7 ± 2.8) nmol/L.
Conclusion: DHA and metabolites can activate BK channels and dilate coronary arteries through activating cytochrome P450 epoxygenase pathway.
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http://dx.doi.org/10.3760/cma.j.issn.0253-3758.2011.04.014 | DOI Listing |
Alzheimers Dement
December 2024
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Background: Accumulating evidence has shown the neuroprotective effects of estrogen on cognition function, for example delaying the cognitive deterioration in patients with Alzheimer's disease (AD). However, the clinical usage of estrogen in AD remains controversial. The cytochrome P450 aromatase encoded by CYP19A1, is a key enzyme catalyzing the C19 androgen conversion to C18 estrogen, which induces testosterone to estradiol and androstenedione to estrone.
View Article and Find Full Text PDFPhysiol Plant
January 2025
Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Copenhagen, Denmark.
Cytochrome P450s of the CYP79 family catalyze two N-hydroxylation reactions, converting a selected number of amino acids into the corresponding oximes. The sorghum genome (Sorghum bicolor) harbours nine CYP79A encoding genes, and here sequence comparisons of the CYP79As along with their substrate recognition sites (SRSs) are provided. The substrate specificity of previously uncharacterized CYP79As was investigated by transient expression in Nicotiana benthamiana and subsequent transformation of the oximes formed into the corresponding stable oxime glucosides catalyzed by endogenous UDPG-glucosyltransferases (UGTs).
View Article and Find Full Text PDFEur Rev Med Pharmacol Sci
December 2024
Department of Pharmacology & Therapeutics, College of Medicine and Health Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain.
Objective: CYP2D6 plays a critical role in metabolizing tamoxifen into its active metabolite, endoxifen, which is crucial for its therapeutic effect in estrogen receptor-positive breast cancer. Single nucleotide polymorphisms (SNPs) in the CYP2D6 gene can affect enzyme activity and thus impact tamoxifen efficacy. This study aimed to use machine learning algorithms (MLAs) to identify significant predictors of Breast Cancer-Free Interval (BCFI) and to apply bioinformatics tools to investigate the structural and functional implications of CYP2D6 SNPs.
View Article and Find Full Text PDFRespir Res
January 2025
Emergency Department, The First Hospital of China Medical University, No.155 North Nanjing Street, Heping District, Shenyang, Liaoning, 110001, China.
Background: We sought to explore the molecular mechanisms underpinning acute lung injury (ALI) caused by poisoning with paraquat (PQ).
Methods: Selection mice were intraperitoneally injected with PQ at 40 mg/kg, whereas controls were injected with sterile saline. On days 2, 7, and 14 after administration, mice were anesthetized and sacrificed, and lung tissue was removed.
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