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Background: Cytochrome-P450 eicosanoids from arachidonic acid, including vasodilator epoxyeicosatrienoic acids (EETs) and the vasoconstrictor 20-HETE, are important in regulating blood pressure, vascular tone, and cardiac and renal function. This study examined plasma 20-HETE and EETs in relation to blood pressure and vascular stiffness in a cohort of 1054 community-dwelling young adults from the Raine Study at 27 years., Methods: Plasma 20-HETE, EETs, and their hydroxylated products were measured by liquid chromatography-tandem mass spectrometry. Pulse wave velocity and aortic distensibility were measured to assess vascular stiffness. Sex differences were assessed using univariate analysis. Multiple regression models assessed the relationship between 20-HETE and systolic blood pressure (SBP) and measures of vascular stiffness., Results: The regression model for SBP showed a positive relationship with plasma 20-HETE (β, 0.092; P <0.0001), after adjusting for sex ( P <0.0001), body mass index ( P <0.0001), (ln)triglycerides ( P <0.0001), and (ln)Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) ( P =0.015), and accounted for 29% of the variance in SBP. 20-HETE was positively related to pulse wave velocity (β, 0.059; P =0.021); after adjusting for sex ( P <0.0001), SBP ( P <0.0001), (ln)triglycerides ( P =0.014), (ln)HOMA-IR ( P =0.0001), (ln)high-sensitivity C-reactive protein ( P =0.005), and age ( P =0.002), the model accounted for 34% of the variance in pulse wave velocity. 20-HETE was inversely associated with aortic distensibility (β, -0.051; P =0.029), independent of sex ( P <0.0001), SBP ( P <0.0001), and (ln)HOMA-IR ( P <0.0001); the model accounted for 25% of the variance in aortic distensibility. Plasma EETs were not significant predictors of SBP or vascular stiffness., Conclusions: In young adults, 20-HETE may play a fundamental role in regulating blood pressure and vascular stiffness independent of numerous cardiometabolic risk factors and cytochrome 450-derived EETs., Registration: URL: https://www.anzctr.org.au; Unique identifier: CTRN12617001599369., Competing Interests: None.

Background: Cardiovascular effects of alcohol consumption may be influenced by both pro- and anti-inflammatory mechanisms. We previously showed that chronic alcohol consumption increased blood pressure (BP), oxidative stress, and 20-hydroxyeicosatetraenoic acid (20-HETE), a vasoconstrictor and pro-inflammatory eicosanoid synthesized by cytochrome P450 (CYP450) enzymes from arachidonic acid. This study in men examined the effect of consuming red wine (RW) on BP in relation to changes in 20-HETE, oxidative stress (F 2 -isoprostanes), markers of inflammation, anti-inflammatory CYP450 epoxyeicosatrienoic acids (EETs), and specialized pro-resolving mediators of inflammation (SPMs) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)., Methods: Normotensive men (n = 22) were randomly allocated to drink RW (375 ml/d) or the equivalent volume of dealcoholized red wine (DRW) or water for 4 weeks in a 12-week, 3-period crossover trial. BP, heart rate, 20-HETE, F 2 -isoprostanes, and SPM were measured at baseline, 4, 8, and 12 weeks., Results: Drinking RW increased BP (p < 0.05), plasma and urinary 20-HETE (p < 0.05), plasma F 2 -isoprostanes (p < 0.0001), and the SPMs 18-hydroxyeicosapentaenoic acid (18-HEPE) from EPA, and resolvin D1 (RvD1) and 17R-resolvin D1 (17R-RvD1) from DHA (all p < 0.05) compared with DRW and water. EETs and high-sensitivity C-reactive protein were unaffected by RW. Plasma 18-HEPE was positively related to urinary 20-HETE (p < 0.008) only after RW., Conclusions: This study has shown that men consuming moderate-to-high alcohol as RW for 4 weeks had increased BP, 20-HETE, and oxidative stress, as well as specific SPM that resolve inflammation. These paradoxical findings require further studies to determine whether alcohol stimulates different CYP450 enzymes and whether the findings can be replicated in females., (Copyright © 2017 by the Research Society on Alcoholism.)

Background: Metabolism of arachidonic acid by cytochrome P450 ω-hydroxylase leads to the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) that regulates vascular function, sodium homeostasis and blood pressure (BP). Supplementation with n-3 fatty acids is known to alter arachidonic acid metabolism and reduce the formation of the lipid peroxidation products F2-isoprostanes, but the effect of n-3 fatty acids on 20-HETE has not been studied., Method: We previously reported a significant effect of n-3 fatty acids but not coenzyme Q10 (CoQ) to reduce BP in a double-blind, placebo-controlled intervention, wherein patients with chronic kidney disease (CKD) were randomized to n-3 fatty acids (4 g), CoQ (200 mg), both supplements or control (4 g olive oil), daily for 8 weeks. This study examined the effect of n-3 fatty acids on plasma and urinary 20-HETE in the same study, as well as plasma and urinary F2-isoprostanes, and relate these to changes in BP., Results: Seventy-four patients completed the 8-week intervention. n-3 fatty acids but not CoQ significantly reduced plasma 20-HETE (P = 0.001) and F2-isoprostanes (P < 0.001). In regression models adjusted for BP at baseline, postintervention plasma 20-HETE was a significant predictor of the fall in SBP (P < 0.0001) and DBP (P < 0.0001) after n-3 fatty acids., Conclusion: This is the first report that n-3 fatty acid supplementation reduces plasma 20-HETE in humans and that this associates with reduced BP. These results provide a plausible mechanism for the reduction in BP observed in patients with CKD following n-3 fatty acid supplementation.

Background: Genetic background partly determines the efficacy of interventions to lower blood pressure (BP). The CYP4F2 and CYP4A11 enzymes are renal 20-hydroxyeicosatetraenoic acid (20-HETE) synthases that regulate BP. Gene variants of CYP4F2 and CYP4A11 associate with hypertension and stroke. We showed that a gene variant of CYP4F2 but not CYP4A11 was associated with increased 20-HETE excretion and BP., Aim: To compare BP and 20-HETE responses in carriers of the CYP4F2 1347G/A polymorphism and controls CYP4F2-GG (wildtype), during weight loss., Methods: Volunteers genotyped as CYP4F2GA/AA (n = 26) and controls genotyped as CYP4F2 GG (n = 27) were counselled to reduce weight for 12 weeks, followed by 4 weeks of weight stabilization. Weight, 24-h BP, pulse pressure and urinary 20-HETE were measured at baseline, 12 and 16 weeks., Results: At baseline, SBP was (+1.7 mmHg, P = 0.047) in the CYP4F2 GA/AA genotype. Compared with baseline, weight fell by 3.9 kg, P = 0.0001, in both genotypes, and was maintained to 16 weeks. SBP fell by (-7.6 mmHg, P = 0.004) in both genotypes after 12 weeks. However, after weight stabilization, SBP was +3.6 mmHg, P = 0.004 in CYP4F2 GA/AA genotype. DBP and heart rate changed similarly over time. Pulse pressure fell with weight loss (P < 0.001), but was elevated in the CYP4F2 GA/AA genotype at all time-points (+3.1 mmHg, P < 0.001). Urinary 20-HETE was similar at baseline and 12 weeks but elevated in the CYP4F2 GA/AA genotype (P = 0.017) after weight stabilization., Conclusion: Maintenance of lower BP after weight loss is more difficult for carriers of the CYP4F2 G1347A polymorphism and may be related to increased arterial stiffness and increased 20-HETE synthesis.

Objective: The vasodilation accompanying acute alcohol ingestion is hard to reconcile with the strong evidence linking chronic alcohol consumption with hypertension. Cytochrome P450 (CYP450) eicosanoids derived from arachidonic acid include vasodilator epoxyeicosatrienoic acids (EETs) and the vasoconstrictor 20-hydroxyeicosatrienoic acid (20-HETE). This study aimed to examine the relationship between CYP450 eicosanoids and blood pressure (BP), and compared the effect of single session of drinking red wine with de-alcoholized red wine (DRW) or water over 24 h., Methods: Twenty-five normotensive men were randomly assigned to drink either 375 ml of red wine (41 g of alcohol) or the equivalent volume of DRW or water, with a light meal on 3 separate days. Ambulatory BP and heart rate were measured over 24 h. Blood samples were obtained before and 2, 4 and 24 h after beverage consumption., Results: Blood pressure fell in the first 4 h after red wine consumption (P = 0.001), but was significantly higher after 20 h (P = 0.037). Plasma 20-HETE fell in the 2 h after consumption of all beverages, but over the 24-h period was relatively higher after red wine consumption (P = 0.025). The largest difference in 20-HETE was 2 h after consuming red wine and coincided with the highest blood alcohol level. There were no significant effects of red wine on plasma EETs., Conclusion: Acute consumption of alcohol as red wine results in a relative increase in plasma levels of the vasoconstrictor 20-HETE over 24 h without affecting EETs, and may contribute to the BP elevation that associates with a binge drinking pattern or be a homeostatic response to the acute fall in BP induced by alcohol.

Arachidonic acid is a major fatty acid that can be metabolized by the cytochrome P450 enzyme to a number of bioactive eicosanoids. A major metabolite of this oxidation is 20-hydroxyeicosatetraenoic acid, which acts as a potent vasoconstrictor. However, in the kidney, its vasoconstrictor actions can be offset by its natriuretic properties. A guanine-to-adenine polymorphism in the CYP4F2 gene was associated with a reduction in 20-hydroxyeicosatetraenoic acid production in vitro. A thymidine-to-cytosine polymorphism in the CYP4A11 gene reduced catalytic activity by >50% in vitro and was associated with hypertension. The aim was to determine whether these 2 mutations are associated with urinary 20-hydroxyeicosatetraenoic acid excretion and blood pressure in humans. For the CYP4F2, 51% were homozygous for the G allele, 40% were carriers, and 9% were homozygous for the A allele. For CYP4A11, 72% were homozygous for the T allele, 25% were carriers, and 3% were homozygous for the C allele. The CYP4F2 GA/AA genotype was significantly associated with an increase in both 20-hydroxyeicosatetraenoic acid excretion and systolic blood pressure. The CYP4A11 CC/TC genotype was significantly associated with a reduction in 20-hydroxyeicosatetraenoic acid excretion but was not associated with blood pressure. We have demonstrated for the first time in humans that polymorphisms of the CYP4F2 and CYP4A11 genes have opposite effects on 20-hydroxyeicosatetraenoic acid excretion. The positive association between the CYP4F2 GA/AA genotype and both systolic blood pressure and 20-hydroxyeicosatetraenoic acid excretion strengthens a role for 20-hydroxyeicosatetraenoic acid in the modulation of blood pressure.

n--3 Fatty acids derived from fish oil reduce plasma triacylglycerols (triglycerides) and increase HDL-C (high-density lipoprotein cholesterol); however, the effect of n--3 fatty acid supplementation during pregnancy, a hyperlipidaemic state, remains unknown. We took the opportunity to investigate maternal lipid levels and blood pressure during and after pregnancy, and fetal lipid levels at birth, in a study that aimed primarily to examine the effect of fish oil supplementation during pregnancy on immune function in infants born to women with allergic disease. Eighty-three pregnant women who had allergic disease, but were otherwise healthy, completed the study. They were randomly allocated to receive fish oil or olive oil capsules, taken as 4 g/day, from 20 weeks of pregnancy until delivery. Compared with olive oil, fish oil supplementation did not alter triacylglycerols, total cholesterol, LDL-C (low-density lipoprotein cholesterol) or HDL-C during or after pregnancy. There was also no effect of fish oil on cord blood triacylglycerols, total cholesterol, LDL-C or HDL-C. Fish oil supplementation during pregnancy did not alter maternal blood pressure during or after pregnancy. The effects of fish oil on lipids and blood pressure in non-pregnant individuals appear to be lost when it is administered during pregnancy.

A positive relationship between alcohol consumption and blood pressure (BP) is well-established but the relative effect of specific alcoholic beverages is controversial. This study aimed to determine whether red wine may improve vascular function and have less of an impact on blood pressure because of its high content of antioxidant vasodilator polyphenolic compounds. Healthy normotensive men entered a 4-period crossover study comparing in random order 4 weeks of control-abstinence with similar periods of daily consumption of red wine (375 mL; 39 grams alcohol), de-alcoholized red wine (375 mL), or beer (1125 mL; 41 grams alcohol). Ambulatory systolic BP and diastolic BP and heart rate (HR) were measured together with vascular function as assessed by flow-mediated dilatation (FMD) and glyceryl trinitrate-mediated (GTNMD) dilatation of the brachial artery. The systolic and diastolic BP and HR were not different between control-abstinence and de-alcoholized red wine. However, compared with control-abstinence, both red wine and beer increased awake systolic BP (2.9 and 1.9 mm Hg, respectively; P<0.05) and asleep HR (5.0 and 4.4 bpm; P<0.05). There were no specific effects of red wine, de-alcoholized red wine, or beer on FMD or GTNMD. Daily consumption of approximately 40 grams alcohol as either red wine or beer for 4 weeks results in similar increases in systolic BP and HR. De-alcoholized red wine did not lower BP, and neither red wine nor de-alcoholized red wine influenced vascular function, suggesting that red wine polyphenolics do not have a significant role in mitigating the blood pressure-elevating effects of alcohol in men.

Abstract: There is considerable evidence that chronic moderate-to-high alcohol consumption increases blood pressure. The mechanisms by which this occurs are not clear. Alcohol consumption can induce oxidative stress and cytochrome P450 (CYP450) isoforms that are associated with oxidative stress and may influence vascular tone. To study the role of such mechanisms we examined whether reducing alcohol intake in moderate-to-heavy drinkers (40–110 g/day) resulted in changes in urinary excretion of 20-HETE, a CYP450 metabolite of arachidonic acid, and plasma and urinary F2-isoprostanes as markers of lipid peroxidation. After a 4-week run-in period during which healthy men maintained their usual drinking pattern they were randomized to a two-way crossover intervention study. In each of the 4-week treatment periods subjects either substituted their usual alcohol intake with a 0.9% alcohol beer or maintained their usual alcohol intake. Plasma and urinary F2-isoprostanes and urinary 20-HETE were measured by gas chromatography mass spectrometry, and serum γ-glutamyl transpeptidase (γ-GT) was measured as a biomarker of alcohol consumption, at the end of each study period. Sixteen healthy men age 51.0±2.7 years and with a BMI of 26.4±0.61 kg/m2 completed the study. The reductions in alcohol intake (72.4±5.0 vs 7.9±1.6 g/day, p <0.001) and serum γ-GT (geometric mean 24.4 U/L (95% CI 19.7, 30.2) vs 18.6 U/L (95% CI 15.5, 22.2, p <0.01) were accompanied by a significant fall in blood pressure as well as urinary 20-HETE excretion (158±23 vs 109±19 pmol/mmol creatinine, p <0.001) and plasma F2-isoprostanes (3438±158 vs 2929±145 pmol/L, p =0.01). A substantial reduction in alcohol consumption in healthy men lowered plasma F2-isoprostanes and urinary 20-HETE. Increased oxidative stress and 20-HETE production may be linked, at least in part, to the pathogenesis of alcohol-related hypertension. [Copyright &y& Elsevier]