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Ansari MN, Nigam GK, Bhandari U. Effect of folic Acid on hematological changes in methionine-induced hyperhomocysteinemia in rats. Indian J Pharm Sci 2009; 71:270-5. [PMID: 20490293 PMCID: PMC2865785 DOI: 10.4103/0250-474x.56025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2008] [Revised: 04/23/2009] [Accepted: 05/25/2009] [Indexed: 01/13/2023] Open
Abstract
The present study was designed to investigate the effect of folic acid on homocysteine, lipid profile and hematological changes in methionine-induced hyperhomocysteinemic rats. Hyperhomocysteinemia was induced by methionine (1 g/kg, p.o.) administration for 30 days. Biochemical and hematological observations were further substantiated with histopathological examination. The increase in homocysteine, total cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and triglycerides levels with reduction in the levels of high density lipoprotein in serum were the salient features observed in methionine treated toxicologic control rats (i.e. group II). Hematological observations of the peripheral blood smears of toxicologic rats also showed crenation of red blood cells membrane and significant (P<0.01) increase in total leukocyte count, differential leukocyte count and platelet counts with significant (P<0.01) decrease in the mean hemoglobin levels, as compared to vehicle control rats. Administration of folic acid (100 mg/kg, p.o.) for 30 days to methionine- induced hyperhomocysteinemic rats produced a significant (P< 0.01) decrease in the levels of homocysteine, total cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and triglycerides with significant (P< 0.01) increase in high density lipoprotein-cholesterol levels in serum when compared with toxicologic control rats. The present study, for the first time, investigates the effect of folic acid treatment on hematological changes in rats with methionine-induced hyperhomocysteinemia.
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Affiliation(s)
- M. N. Ansari
- Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi-110 062, India
| | - G. K. Nigam
- Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi-110 062, India
| | - Uma Bhandari
- Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi-110 062, India
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Nigam GK, Ansari MN, Bhandari U. Effect of Rosuvastatin on Methionine-Induced Hyperhomocysteinaemia and Haematological Changes in Rats. Basic Clin Pharmacol Toxicol 2008; 103:287-92. [DOI: 10.1111/j.1742-7843.2008.00293.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Katz DL, Evans MA, Nawaz H, Njike VY, Chan W, Comerford BP, Hoxley ML. Egg consumption and endothelial function: a randomized controlled crossover trial. Int J Cardiol 2005; 99:65-70. [PMID: 15721501 DOI: 10.1016/j.ijcard.2003.11.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 11/16/2003] [Indexed: 10/25/2022]
Abstract
BACKGROUND Because of egg cholesterol content, reduction in egg consumption is generally recommended to reduce risk of cardiovascular disease. Recently, however, evidence has been accumulating to suggest that dietary cholesterol is less relevant to cardiovascular risk than dietary saturated fat. This randomized controlled crossover trial was conducted to determine the effects of egg ingestion on endothelial function, a reliable index of cardiovascular risk. METHODS Forty-nine healthy adults (mean age 56 years, 40% females) underwent a baseline brachial artery reactivity study (BARS), and were assigned to two eggs or oats daily for 6 weeks in random sequence with a 4-week washout. A BARS was done at the end of each treatment phase, measuring flow-mediated vasodilation (FMD) in the brachial artery using a high-frequency ultrasound. RESULTS FMD was stable in both egg and oat groups, and between-treatment differences were not significant (egg -0.96%, oatmeal -0.79%; p value >0.05). Six weeks of egg ingestion had no effect on total cholesterol (baseline: 203.8 mg/dl; post-treatment: 205.3) or LDL (baseline: 124.8 mg/dl; post-treatment: 129.1). In contrast, 6 weeks of oats lowered total cholesterol (to 194 mg/dl; p = 0.0017) and LDL (to 116.6 mg/dl; p = 0.012). There were no differences in body mass index (BMI), triglyceride, HDL or SBP levels between egg and oat treatment assignments. CONCLUSION Short-term egg consumption does not adversely affect endothelial function in healthy adults, supporting the view that dietary cholesterol may be less detrimental to cardiovascular health than previously thought.
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Affiliation(s)
- David L Katz
- Yale Prevention Research Center, 130 Division Street, Derby, CT 06418, USA.
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Meerarani P, Reiterer G, Toborek M, Hennig B. Zinc Modulates PPARγ Signaling and Activation of Porcine Endothelial Cells. J Nutr 2003; 133:3058-64. [PMID: 14519784 DOI: 10.1093/jn/133.10.3058] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dietary zinc has potent antioxidant and anti-inflammatory properties and is a critical component of peroxisome proliferator-activated receptor (PPAR) gene expression and regulation. To assess the protective mechanisms of PPARgamma in endothelial cell dysfunction and the role of zinc in the modulation of PPARgamma signaling, cultured porcine pulmonary artery endothelial cells were exposed to the membrane-permeable zinc chelator N,N,N'N'-tetrakis (2-pyridylmethyl)-ethylene diamine (TPEN), thiazolidinedione (TZD; PPARgamma agonist) or bisphenol A diglycidyl ether (BADGE; PPARgamma antagonist). Subsequently, endothelial cells were activated by treatment with linoleic acid (90 micro mol/L) for 6 h. Zinc chelation by TPEN increased the DNA binding activity of nuclear factor (NF)-kappaB and activator protein (AP)-1, decreased PPARgamma expression and activation as well as up-regulated interleukin (IL)-6 expression and production. These effects were fully reversed by zinc supplementation. In addition, exposure to TZD down-regulated linoleic acid-induced DNA binding activity of NF-kappaB and AP-1, whereas BADGE further induced activation of these oxidative stress-sensitive transcription factors. Most importantly, the TZD-mediated down-regulation of NF-kappaB and AP-1 and reduced inflammatory response were impaired during zinc chelation. These data suggest that zinc plays a critical role in PPARgamma signaling in linoleic acid-induced endothelial cell activation and indicate that PPARgamma signaling is impaired during zinc deficiency.
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Affiliation(s)
- Purushothaman Meerarani
- Molecular and Cell Nutrition Laboratory, College of Agriculture, University of Kentucky, Lexington, KY 40546-0215, USA
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Rabini RA, Vignini A, Salvolini E, Staffolani R, Martarelli D, Moretti N, Mazzanti L. Activation of human aortic endothelial cells by LDL from Type 1 diabetic patients: an in vitro study. Atherosclerosis 2002; 165:69-77. [PMID: 12208472 DOI: 10.1016/s0021-9150(02)00197-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An altered interaction between circulating LDL and endothelial cells might be at the basis of the increased prevalence of atherosclerosis in diabetes mellitus. The aim of the present work was to investigate the effect of a short incubation period with LDL from Type 1 diabetic patients in good metabolic control on endothelial cells derived from human aorta (HAEC). Cultured HAEC were incubated for 3 h with culture medium alone (control HAEC), with native LDL from healthy subjects (control LDL), or with native LDL from Type 1 diabetic patients (Type 1 LDL). After the incubation the following parameters were evaluated: endothelial cell nitric oxide synthase (NOS) activity, nitric oxide (NO) and peroxynitrite production, Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities, intracellular Ca(2+) concentration and fluidity of the superficial part of the plasma membrane studied by 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). Moreover, we studied the cellular activation, evaluated by the fluid phase endocytosis of TMA-DPH, and the microetherogeneity of the membrane surface, evaluated by dynamic fluorescence. HAEC incubated with control LDL showed compared with control HAEC: increased anisotropy and exponential lifetime of TMA-DPH, and enhanced TMA-DPH internalization. HAEC incubated with Type 1 LDL showed compared with both control HAEC and HAEC incubated with control LDL: (i) increased Na(+)/K(+)-ATPase and Ca(2+)-ATPase activities, and intracellular Ca(2+) concentration; (ii) increased NOS activity, NO and peroxynitrite production; (iii) increased anisotropy of TMA-DPH; (iv) enhanced internalization of the probe. The exponential lifetime and the width of distribution of TMA-DPH were significantly increased by Type 1 LDL only in comparison with control HAEC. The results suggest that a short-term interaction with LDL from Type 1 diabetic patients causes alterations of the plasma membrane surface and of cellular functions in endothelial cells in a possibly atherogenic way.
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Affiliation(s)
- Rosa A Rabini
- Department of Diabetology, Italian National Research Center on Aging, Ancona, Italy
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Abstract
Thrombophilias are inherited or acquired conditions that predispose individuals to thromboembolism. New inherited thrombophilias are recognized each year. Some, but not all, studies have found an association between inherited thrombophilias and adverse pregnancy outcomes, including fetal loss. The controversy regarding the clinical implications of thrombophilias in pregnancy is clouded by differences in study populations, the number of thrombophilias tested, interactions between thrombophilias, and the retrospective nature of most studies, just to name a few factors. The lack of adequately designed studies also extends to clinical management. Clear evidence to determine when to test, whom to test, which thrombophilias to test for, when to treat, and what to treat with is not available. Further studies to investigate these questions are urgently needed.
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Affiliation(s)
- George R Saade
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, USA.
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Ballesteros MN, Cabrera RM, Saucedo MS, Yepiz-Plascencia GM, Ortega MI, Valencia ME. Dietary fiber and lifestyle influence serum lipids in free living adult men. J Am Coll Nutr 2001; 20:649-55. [PMID: 11771682 DOI: 10.1080/07315724.2001.10719163] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE The aim of this study was to determine the effect of dietary fiber consumption and lifestyle on serum lipids in adult men with non-restricted diet and physical activity. METHODS Two groups of 19 men were classified as high (48 g/day) and low fiber groups (27 g/day). Anthropometry, food frequency, daily weighed intakes and physical activity were done for a seven-day period. Fasting blood was collected and serum was analyzed for triglycerides, total cholesterol and lipoprotein cholesterol fractions. RESULTS Crude correlation coefficients showed that total cholesterol was negatively associated with physical activity, total dietary fiber and P/S ratio (r = 0.52; p < 0.001. r = -0.44; p < 0.01, r = 0.51, p < 0.001). LDL-C was also correlated negatively with total dietary fiber and P/S ratio (r = -0.34, p < 0.03; r = -0.53, p < 0.01). It was also positively associated with dietary cholesterol and body weight (r = 0.34, p < 0.03; r = 0.31, p < 0.05). Serum triglycerides had an inverse association with total dietary fiber and physical activity (r = -0.30: p < 0.05; r = -0.45, p < 0.004). After controlling for energy intake, total fat, saturated fat, dietary cholesterol, physical activity and body mass index, LDL-C/HDL-C, and TC/HDL-C, remained significantly associated with dietary fiber (r = 0.34; p < 0.05 and r = -0.38; p < 0.02, respectively). CONCLUSIONS This study provides evidence in free living men that there is an association between dietary fiber intake and favorable lipid status and that lifestyle defined by socioeconomic status, physical activity and the quality of the dietary fat intake can play an important role. Public health nutrition advice and policy should continue to emphasize the importance of these factors.
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Affiliation(s)
- M N Ballesteros
- Department of Human Nutrition, Centro de Investigación en Alimentación y Desarrollo, A.C. Hernosillo, Sonora, Mexico.
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Dagher Z, Ruderman N, Tornheim K, Ido Y. Acute regulation of fatty acid oxidation and amp-activated protein kinase in human umbilical vein endothelial cells. Circ Res 2001; 88:1276-82. [PMID: 11420304 DOI: 10.1161/hh1201.092998] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is generally accepted that endothelial cells generate most of their ATP by anaerobic glycolysis and that very little ATP is derived from the oxidation of fatty acids or glucose. Previously, we have reported that, in cultured human umbilical vein endothelial cells (HUVECs), activation of AMP-activated protein kinase (AMPK) by the cell-permeable activator 5-aminoimidazole-4-carboximide riboside (AICAR) is associated with an increase in the oxidation of (3)H-palmitate. In the present study, experiments carried out with cultured HUVECs revealed the following: (1) AICAR-induced increases in palmitate oxidation during a 2-hour incubation are associated with a decrease in the concentration of malonyl coenzyme A (CoA) (an inhibitor of carnitine palmitoyl transferase 1), which temporally parallels the increase in AMPK activity and a decrease in the activity of acetyl CoA carboxylase (ACC). (2) AICAR does not stimulate either palmitate oxidation when carnitine is omitted from the medium or oxidation of the medium-chain fatty acid octanoate. (3) When intracellular lipid pools are prelabeled with (3)H-palmitate, the measured rate of palmitate oxidation is 3-fold higher, and in the presence of AICAR, it accounts for nearly 40% of calculated ATP generation. (4) Incubation of HUVECs in a glucose-free medium for 2 hours causes the same changes in AMPK, ACC, malonyl CoA, and palmitate oxidation as does AICAR. (5) Under all conditions studied, the contribution of glucose oxidation to ATP production is minimal. The results indicate that the AMPK-ACC-malonyl CoA-carnitine palmitoyl transferase 1 mechanism plays a key role in the physiological regulation of fatty acid oxidation in HUVECs. They also indicate that HUVECs oxidize fatty acids from both intracellular and extracellular sources, and that when this is taken into account, fatty acids can be a major substrate for ATP generation. Finally, they suggest that AMPK is likely to be a major factor in modulating the response of the endothelium to stresses that alter its energy state.
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Affiliation(s)
- Z Dagher
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
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Martin KR, Wu D, Meydani M. The effect of carotenoids on the expression of cell surface adhesion molecules and binding of monocytes to human aortic endothelial cells. Atherosclerosis 2000; 150:265-74. [PMID: 10856518 DOI: 10.1016/s0021-9150(99)00375-5] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Several large epidemiological studies have shown a correlation between elevated plasma carotenoid levels and decreased risk of cardiovascular disease (CVD). One proposed mechanism for the beneficial effect of carotenoids is through functional modulation of potentially atherogenic processes associated with the vascular endothelium. To test this, we incubated confluent human aortic endothelial cell (HAEC) cultures (passages 4-8) for 24 h with each of the five most prevalent carotenoids in human plasma, which are alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and lycopene, at an approximate concentration of 1 micromol/l. Carotenoids were solubilized in 0.7% (v/v) tetrahydrofuran and incorporated into FBS before adding to cell culture medium. Due to disparate solubilities in aqueous medium, final concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and lycopene were 1.7, 1.1, 0.7, 0.9, and 0.3 micromol/l and monolayers accumulated 647, 158, 7, 113, and 9 pmol/mg protein, respectively. Monolayers were then stimulated with IL-1beta (5 ng/ml) for 6 h with subsequent determination of cell surface expression of adhesion molecules as measured by an enzyme-linked immunosorbent assay (ELISA). To assess endothelial cell adhesion to monocytes, IL-1beta-stimulated monolayers were incubated for 10 min with 51Cr-labeled U937 monocytic cells and adhesion determined by isotope counting. Pre-incubation of HAEC with beta-carotene, lutein and lycopene significantly reduced VCAM-1 expression by 29, 28, and 13%, respectively. Pre-incubation with beta-carotene and lutein significantly reduced E-selectin expression by 38 and 34%, respectively. Pre-treatment with beta-carotene, lutein and lycopene significantly reduced the expression of ICAM-1 by 11, 14, and 18%, respectively. While other carotenoids were ineffective, lycopene attenuated both IL-1beta-stimulated and spontaneous HAEC adhesion to U937 monocytic cells by 20 and 25%, respectively. Thus, among the carotenoids, lycopene appears to be most effective in reducing both HAEC adhesion to monocytes and expression of adhesion molecules on the cell surface.
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Affiliation(s)
- K R Martin
- Vascular Biology Program, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, 02111, Boston, MA, USA
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George J, Mulkins M, Casey S, Schatzman R, Sigal E, Harats D. The effects of N-6 polyunsaturated fatty acid supplementation on the lipid composition and atherogenesis in mouse models of atherosclerosis. Atherosclerosis 2000; 150:285-93. [PMID: 10856520 DOI: 10.1016/s0021-9150(99)00377-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Despite numerous studies, the precise role of dietary n-6 polyunsaturated fatty acids in the pathogenesis of atherosclerosis remains controversial. It has been shown that feeding an n-6-enriched diet resulted in decreased atherosclerosis in African green monkeys and was associated with a reduction in LDL levels. However, other authors reported that n-6 supplementation increased the oxidative stress and the susceptibility of LDL to undergo in vitro oxidation, thus potentially enhancing atherosclerosis. The present study was designed to investigate the effect of dietary supplementation of n-6 polyunsaturated fats (safflower oil), as compared with a saturated fat-rich diet (Paigen), on the blood lipid profile and atherosclerosis in two mouse models. In the first experiment, female C57BL/6 mice (n=23-30 per group) were fed a cholate containing Paigen diet, a safflower oil-rich diet (with cholate), or normal chow for 15 weeks. No significant differences between the high fat diet groups were evident with respect to total cholesterol, LDL, HDL or triglyceride levels. The extent of aortic sinus fatty streaks did not differ significantly between the two groups. In the second experiment, LDL-receptor-deficient (LDL-RD) mice (n=20-30 per group) were randomized into similar dietary regimens. Mice consuming a safflower oil-enriched diet developed significantly less atherosclerosis, in comparison with Paigen diet-fed mice. A reduction in LDL levels, although not of a similar magnitude as the reduction in atherosclerosis, was evident in the safflower oil-fed mice when compared to the Paigen diet-fed littermates. In both mouse models of atherosclerosis, LDL isolated from the plasma of mice on the n-6 polyunsaturated diet was rendered slightly more susceptible to oxidation in vitro, as indicated by a shorter lag period for diene formation. Thus, the effects of n-6 fatty acids on the lipoprotein composition and other potential influences may have contributed to the anti-atherogenic effect in the LDL-RD mouse model.
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MESH Headings
- Animals
- Aorta/drug effects
- Aorta/pathology
- Arteriosclerosis/blood
- Arteriosclerosis/chemically induced
- Arteriosclerosis/diet therapy
- Arteriosclerosis/pathology
- Body Weight
- Diet, Atherogenic
- Dietary Fats, Unsaturated/administration & dosage
- Dietary Supplements
- Disease Progression
- Fatty Acids, Omega-6
- Fatty Acids, Unsaturated/administration & dosage
- Female
- Lipoproteins, LDL/blood
- Lipoproteins, LDL/drug effects
- Mice
- Mice, Inbred C57BL
- Oxidative Stress/drug effects
- Random Allocation
- Receptors, LDL/blood
- Receptors, LDL/deficiency
- Receptors, LDL/drug effects
- Safflower Oil/administration & dosage
- Triglycerides/blood
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Affiliation(s)
- J George
- Institute of Lipid and Atherosclerosis Research, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, 52621, Tel Hashomer, Israel
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Meerarani P, Ramadass P, Toborek M, Bauer HC, Bauer H, Hennig B. Zinc protects against apoptosis of endothelial cells induced by linoleic acid and tumor necrosis factor alpha. Am J Clin Nutr 2000; 71:81-7. [PMID: 10617950 DOI: 10.1093/ajcn/71.1.81] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Zinc requirements of the vascular endothelium may be increased in inflammatory conditions, ie, atherosclerosis, in which apoptotic cell death is prevalent. OBJECTIVE We hypothesized that zinc deficiency may potentiate disruption of endothelial cell integrity mediated by fatty acids and inflammatory cytokines by enhancing pathways that lead to apoptosis and up-regulation of caspase genes. DESIGN Endothelial cells were maintained in low-serum medium or grown in culture media containing selected chelators, ie, diethylenetriaminepentaacetate or N,N,N', N'-tetrakis(2-pyridylmethyl)-ethylenediamine (TPEN), with or without zinc supplementation. Subsequently, cells were treated with linoleic acid, tumor necrosis factor alpha (TNF-alpha), or both. We studied the effect of zinc deficiency and supplementation on the induction of apoptosis by measuring caspase-3 activity, cell binding of annexin V, and DNA fragmentation. RESULTS Our results indicated that linoleic acid and TNF-alpha independently, but more markedly in concert, up-regulated caspase-3 activity and induced annexin V binding and DNA fragmentation. Zinc deficiency, especially when induced by TPEN, dramatically increased apoptotic cell death induced by cytokines and lipids compared with control cultures. Supplementation of low-serum- or chelator-treated endothelial cells with physiologic amounts of zinc caused a marked attenuation of apoptosis induced by linoleic acid and TNF-alpha. Morphologic changes of cells observed during zinc deficiency were prevented by zinc supplementation. Media supplementation with other divalent cations (eg, calcium and magnesium) did not mimic the protective role of zinc against apoptosis. CONCLUSIONS Our data indicate that zinc is vital to vascular endothelial cell integrity, possibly by regulating signaling events to inhibit apoptotic cell death.
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Affiliation(s)
- P Meerarani
- Departments of Nutrition and Food Science and Surgery, University of Kentucky, Lexington, and the Molecular Biology Institute, Austrian Academy of Sciences, Salzburg
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Gerber RT, Holemans K, O'Brien-Coker I, Mallet AI, van Bree R, Van Assche FA, Poston L. Cholesterol-independent endothelial dysfunction in virgin and pregnant rats fed a diet high in saturated fat. J Physiol 1999; 517 ( Pt 2):607-16. [PMID: 10332106 PMCID: PMC2269352 DOI: 10.1111/j.1469-7793.1999.0607t.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
1. Western diets high in saturated fat are associated with an increased incidence of cardiovascular diseases. In this study we have evaluated vascular endothelial function and oxidative stress in virgin rats fed a normal (VC) or high in saturated fat diet (VHF) (20 % lard and corn oil w/w) from weaning until adulthood, and throughout subsequent pregnancy (PC and PHF, respectively). 2. The saturated fat diet was associated with enhanced noradrenaline sensitivity in small mesenteric arteries from VHF rats (VHF vs. VC, P < 0.05) and blunted endothelium-dependent relaxation in VHF and PHF rats (VHF vs. VC, P < 0.001; PHF vs. PC, P < 0.05). Endothelial dysfunction was attributable to a reduced nitric oxide component of relaxation in VHF rats, and blunted prostacyclin and endothelium-derived hyperpolarizing factor components in PHF rats. 3. Other than plasma cholesterol, which was reduced in VHF and PHF rats, plasma lipids were normal. Fasting plasma insulin and glucose concentrations were raised in VHF rats (P < 0.05) and the plasma marker of oxidative stress, 8-iso PGF2alpha, was increased in PHF animals (P < 0.01). 4. These findings suggest that endothelial dysfunction induced by a saturated fat diet is cholesterol independent and likely to be of different mechanistic origin in virgin and pregnant rats.
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Affiliation(s)
- R T Gerber
- Department of Obstetrics and Gynaecology, Guy's, King's and St Thomas' School of Medicine (GKT), St Thomas' Hospital, London, UK
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Chizzolini R, Zanardi E, Dorigoni V, Ghidini S. Calorific value and cholesterol content of normal and low-fat meat and meat products. Trends Food Sci Technol 1999. [DOI: 10.1016/s0924-2244(99)00034-5] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hennig B, Meerarani P, Toborek M, McClain CJ. Antioxidant-like properties of zinc in activated endothelial cells. J Am Coll Nutr 1999; 18:152-8. [PMID: 10204831 DOI: 10.1080/07315724.1999.10718843] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE The objective of this study was to test the hypothesis that zinc deficiency in endothelial cells may potentiate the inflammatory response mediated by certain lipids and cytokines, possibly via mechanisms associated with increased cellular oxidative stress. Our experimental approach was to compare conditions of cellular zinc deficiency and zinc supplementation with oxidative stress-mediated molecular and biochemical changes in vascular endothelial cells. METHODS To investigate our hypothesis, porcine pulmonary artery-derived endothelial cells were depleted of zinc by culture in media containing 1% fetal bovine serum for eight days. Subsequently, endothelial cells were exposed to media enriched with or without zinc (10 microM) for two days, followed by exposure to either tumor necrosis factor-alpha (TNF, 500 U/mL) or linoleic acid (90 microM), before measurement of oxidative stress (DCF fluorescence), activation of nuclear factor kappaB (NF-kappaB) or activator protein-1 (AP-1) and production of the inflammatory cytokine interleukin 6 (IL-6). RESULTS Oxidative stress was increased markedly in zinc-deficient endothelial cells following treatment with fatty acid or TNF. This increase in oxidative stress was partially blocked by prior zinc supplementation. The oxidative stress-sensitive transcription factor NF-kappaB was up-regulated by zinc deficiency and fatty acid treatment. The up-regulation mediated by fatty acids was markedly reduced by zinc supplementation. Similar results were obtained with AP-1. Furthermore, endothelial cell production of IL-6 was increased in zinc-deficient endothelial cells following treatment with fatty acids or TNF. This increase in production of inflammatory cytokines was partially blocked by zinc supplementation. DISCUSSION Our previous data clearly show that zinc is a protective and critical nutrient for maintenance of endothelial integrity. The present data suggest that zinc may in part be antiatherogenic by inhibiting oxidative stress-responsive events in endothelial cell dysfunction. This may have implications in understanding mechanisms of atherosclerosis.
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Affiliation(s)
- B Hennig
- Department of Nutrition and Food Science, University of Kentucky, Lexington 40506-0054, USA
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16
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Connell P, Young VM, Toborek M, Cohen DA, Barve S, McClain CJ, Hennig B. Zinc attenuates tumor necrosis factor-mediated activation of transcription factors in endothelial cells. J Am Coll Nutr 1997; 16:411-7. [PMID: 9322188 DOI: 10.1080/07315724.1997.10718706] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The objective of the study was to test the hypothesis that zinc can protect against endothelial dysfunction by interfering with oxidative stress-mediated cellular signaling and subsequent inhibition of an endothelial cell inflammatory response. Our approach was to compare alterations on molecular and biochemical levels with changes in endothelial barrier function that occur in zinc deficient conditions. METHODS To investigate our hypothesis, endothelial cells were exposed to zinc deficient media for 2 to 10 days to deplete cellular zinc stores. Following this, half of the groups received zinc supplementation (9.2 microM) for 48 hours. The other half served as zinc deficient controls. These cells were then challenged with tumor necrosis factor-alpha (TNF) for varying time periods. Nuclear extracts were prepared from cells and analyzed for nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1) binding. Media from cells were analyzed for interleukin 8 (IL-8) production, and cellular proteins were determined. RESULTS Zinc supplementation resulted in a 74% increase in cellular zinc content. It was also shown that a 1.5 hour exposure to TNF (100 U/mL medium) significantly increased NF-kappa B and AP-1 binding, which was lowered considerably when cells were supplemented with physiological levels of zinc. Zinc supplementation also caused a marked attenuation in IL-8 expression by endothelial cells in response to TNF-mediated cell activation. DISCUSSION Our previous data clearly show that zinc is a protective and critical nutrient for maintenance of endothelial integrity. The present data suggest that zinc may protect against cytokine-mediated activation of oxidative stress sensitive transcription factors, upregulation of inflammatory cytokines and endothelial cell dysfunction. This may have implications in understanding mechanisms of atherosclerosis.
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Affiliation(s)
- P Connell
- Multidisciplinary Doctoral Program in Nutritional Sciences, University of Kentucky, Lexington 40506-0054, USA
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17
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Toborek M, Feldman DL, Hennig B. Aortic antioxidant defense and lipid peroxidation in rabbits fed diets supplemented with different animal and plant fats. J Am Coll Nutr 1997; 16:32-8. [PMID: 9013431 DOI: 10.1080/07315724.1997.10718646] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To test the hypothesis that dietary fats, depending on the fat source, may modulate aortic lipid peroxidation and antioxidant protection. METHODS Rabbits were fed a low fat (LF, 2 g/100 g corn oil) diet or LF enriched with 16 g/100 g (w/w) of corn oil (CO), corn oil plus cholesterol (23.5 mg/100 g diet, CO + C), bovine milk fat (MF), chicken fat (CF), beef tallow (BT) or lard (L). After a 30-day feeding period, aortic lipid peroxidation, as well as antioxidant enzymes and vitamin E were measured. RESULTS In rabbits fed CO or L, aortic TBARS (a marker of lipid peroxidation) and total glutathione concentrations were greater but vitamin E levels were lower compared with the LF treatment. Moreover, in rabbits fed CO, elevated activities of glutathione peroxidase and glutathione reductase but lowered activity of superoxide dismutase were observed. In rabbits fed the remaining high fat diets, including the CO + C diet, aortic lipid peroxidation and antioxidant activities/levels did not differ from those fed LF. Feeding rabbits high-fat diets for 30 days did not induce aortic lipid deposition. CONCLUSIONS The present results indicate CO, and possibly L, as the fat sources which significantly increase aortic oxidative stress. Because long-term disturbances in redox status may be implicated in atherogenesis, excessive dietary intake of CO or L may significantly contribute to the injury of the vessel wall.
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Affiliation(s)
- M Toborek
- Department of Surgery, University of Kentucky Medical Center, Lexington 40536, USA
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18
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Joseph JA, Villalobos-Molinas R, Denisova NA, Erat S, Strain J. Cholesterol: a two-edged sword in brain aging. Free Radic Biol Med 1997; 22:455-62. [PMID: 8981037 DOI: 10.1016/s0891-5849(96)00376-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Previous research from several laboratories has indicated that cholesterol (CHO) accumulates in neuronal membranes and alters their structural and signal transduction (ST) properties during aging. The possible reasons for these increases in membrane CHO have not been specified. However, present findings suggest that such accumulation may actually serve to protect neuronal tissue from oxidative damage. Striatal slices (6, 24 month rats) were preincubated in 1 mM CHO (30 min) followed by incubation with H2O2 (10 microM, 30 min). The slices were then either superfused with 30 mM KCl in the presence or absence of 500 microM oxotremorine (Ox), and K(+)-evoked dopamine release (K(+)-ERDA) examined or assessed for carbachol-stimulated low K(m) GTPase activity. The results indicated that CHO incubation prior to H2O2 in either age group was effective in preventing H2O2 reductions in both non-Ox-enhanced K(+)-ERDA and Ox conditions, as well as sodium nitroprusside (SNP 150 microM)-induced decreases in K(+)-ERDA. In addition, H2O2-induced deficits in carbachol-stimulated low K(m) GTPase activity were reduced in the striatal tissue from the old animals pretreated with CHO. However, if the slices were incubated in H2O2 prior to CHO exposure, CHO enhanced the H2O2 effects in the tissue from the old animals. Thus, depending upon the order of exposure, CHO functioned to enhance or retard the effects of oxidative stress, in an age-dependent manner.
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Affiliation(s)
- J A Joseph
- USDA-ARS Human Nutrition Research Center on Aging, Boston, MA 02111, USA
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19
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Toborek M, Hennig B. Is endothelial cell autocrine production of tumor necrosis factor a mediator of lipid-induced endothelial dysfunction? Med Hypotheses 1996; 47:377-82. [PMID: 8951801 DOI: 10.1016/s0306-9877(96)90217-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Injury or dysfunction of the vascular endothelium is one of the first events in the development of atherosclerosis. Individual lipids, e.g. fatty acids or lipoproteins, are among the most critical factors which may induce injury to the endothelium. Selected fatty acids, such as linoleic acid, can disrupt endothelial barrier function and increase the inflammatory response of the vascular endothelium. The mechanisms of these processes are not fully understood. It is hypothesized that selected fatty acids can mediate the autocrine production of tumor necrosis factor-alpha in endothelial cells. This will activate a variety of intracellular signaling pathways and further potentiate endothelial injury initially induced by fatty acids.
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Affiliation(s)
- M Toborek
- Department of Surgery, University of Kentucky Medical Center, Lexington 40536, USA
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20
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Hennig B, Toborek M, Mcclain CJ. Antiatherogenic properties of zinc: implications in endothelial cell metabolism. Nutrition 1996; 12:711-7. [PMID: 8936496 DOI: 10.1016/s0899-9007(96)00125-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Zinc is an essential component of biomembranes and is necessary for maintenance of membrane structure and function. There is evidence that zinc can provide antiatherogenic properties by preventing metabolic physiologic derangements of the vascular endothelium. Because of its antioxidant and membrane-stabilizing properties, zinc appears to be crucial for the protection against cell-destabilizing agents such as polyunsaturated lipids and inflammatory cytokines. Zinc also may be antiatherogenic by interfering with signaling pathways involved in apoptosis. Most importantly, we have evidence that zinc can protect against inflammatory cytokine-mediated activation of oxidative stress-responsive transcription factors, such as nuclear factor kappa B and AP-1. It is very likely that certain lipids and zinc deficiency may potentiate the cytokine-mediated inflammatory response and endothelial cell dysfunction in atherosclerosis. Thus, the antiatherogenic role of zinc appears to be in its ability to inhibit oxidative stress-responsive factors involved in disruption of endothelial integrity and atherosclerosis. We discuss antiatherogenic properties of zinc with a focus on endothelial cell metabolism.
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Affiliation(s)
- B Hennig
- Department of Nutrition and Food Science, University of Kentucky, Lexington 40506-0054, USA
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21
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Toborek M, Hennig B. Dietary methionine imbalance, endothelial cell dysfunction and atherosclerosis. Nutr Res 1996. [DOI: 10.1016/0271-5317(96)00128-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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22
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Gorman L, Mercer LP, Hennig B. Growth requirements of endothelial cells in culture: variations in serum and amino acid concentrations. Nutrition 1996; 12:266-70. [PMID: 8862533 DOI: 10.1016/s0899-9007(96)90854-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Endothelial cell growth in vitro is limited to the availability of nutrients from commercially available media and added serum. Nutrients, such as amino acids, are chiefly derived from the cell culture medium, rather than from added serum, and optimal endothelial cell growth may be dependent on amino acid levels in the culture media. To test this hypothesis, porcine pulmonary artery-derived endothelial cells were exposed to culture medium 199 (M199), amino acid-deficient M199 (dM199), as well as dM199 supplemented with amino acids. Cell protein was similar in cells cultured for 3 d in M199 supplemented with 1, 3, 5 or 10% bovine calf serum, respectively. Addition of amino acid solutions (L-amino acids [Laa], DL-amino acids [DLaa], 2Laa, or Laa+glutamine) to dM199 demonstrated a cell dependence for optimal growth on the type of amino acids as well as on the total available nitrogen in the media. Compared with M199, dM199 supplemented with Laa only partially supported long-term growth of endothelial cells in culture. On the other hand, dM199 supplemented with either 2Laa, DLaa, or Laa+ glutamine was superior over M199 with regard to endothelial cell growth. The addition of Laa+glutamine to dM199 was most growth-supporting, with an increase of over 2.6-fold in total cell protein compared with cells cultured with M199. These results suggest that, in addition to the presence of essential amino acids, total available nitrogen in culture media may be a critical factor for optimal endothelial cell growth.
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Affiliation(s)
- L Gorman
- Department of Nutrition and Food Science, University of Kentucky, Lexington, Kentucky 40506, USA
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23
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Toborek M, Barger SW, Mattson MP, Barve S, McClain CJ, Hennig B. Linoleic acid and TNF-alpha cross-amplify oxidative injury and dysfunction of endothelial cells. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)37641-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Toborek M, Barger SW, Mattson MP, McClain CJ, Hennig B. Role of glutathione redox cycle in TNF-alpha-mediated endothelial cell dysfunction. Atherosclerosis 1995; 117:179-88. [PMID: 8801863 DOI: 10.1016/0021-9150(95)05568-h] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Modulation of the glutathione redox cycle may influence tumor necrosis factor-alpha (TNF)-mediated disturbances of endothelial integrity. To test this hypothesis, normal endothelial cells or cells with either increased or decreased glutathione levels were exposed to 100 ng (500 U) TNF/ml. Increased glutathione levels were achieved by exposure to 0.2 mM N-acetyl-L-cysteine (NAC) and decreased glutathione levels by exposure to 25 microM buthionine sulfoximine (BSO). Several components of the glutathione redox cycle as well as markers of endothelial integrity, such as cytoplasmic free calcium and transendothelial albumin transfer, were measured in the treated cells. Exposure to TNF for 3 and 6 h decreased total glutathione levels, which was followed by an increase at later time points. Moreover, treatment with TNF resulted in an increase in the ratio of oxidized to reduced glutathione, intracellular free calcium, albumin transfer across endothelial monolayers and lipid hydroperoxides. However, an increase in lipid hydroperoxides was seen only when endothelial cell cultures were supplemented with iron. BSO treatment increased susceptibility of endothelial cells to TNF-mediated metabolic disturbances. On the other hand, NAC partially protected against TNF-induced injury to endothelial monolayers. Our results demonstrate the important role of the glutathione redox cycle in TNF-mediated disturbances of the vascular endothelium and indicate that modulation of glutathione levels may potentiate the injurious effects of this inflammatory cytokine.
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Affiliation(s)
- M Toborek
- Department of Nutrition and Food Science, University of Kentucky, Lexington 40506-0054, USA
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Toborek M, Barger SW, Mattson MP, Espandiari P, Robertson LW, Hennig B. Exposure to polychlorinated biphenyls causes endothelial cell dysfunction. JOURNAL OF BIOCHEMICAL TOXICOLOGY 1995; 10:219-26. [PMID: 8568836 DOI: 10.1002/jbt.2570100406] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Environmental chemicals, such as polychlorinated biphenyls (PCBs), may be atherogenic by disrupting normal functions of the vascular endothelium. To investigate this hypothesis, porcine pulmonary artery-derived endothelial cells were exposed to 3,3',4,4'-tetrachlorobiphenyl (PCB 77), 2,3,4,4',5-pentachlorobiphenyl (PCB 114), or 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) for up to 24 hours. These PCBs were selected for their varying binding avidities with the aryl hydrocarbon (Ah) receptor and differences in their induction of cytochrome P450. PCB 77 and PCB 114 significantly disrupted, in a dose-dependent manner, endothelial barrier function by allowing an increase in albumin transfer across endothelial monolayers. These PCBs also contributed markedly to cellular oxidative stress, as measured by 2,7-dichlorofluorescin (DCF) fluorescence and lipid hydroperoxides, and caused a significant increase in intracellular calcium ([Ca2+]i) levels. Enhanced oxidative stress and [Ca2+]i in PCB 77- and PCB 114-treated cells were accompanied by increased activity and content of cytochrome P450 1A and by a decrease in the vitamin E content in the culture medium. In contrast to the effects of PCB 77 and PCB 114, cell exposure to PCB 153 had no effect on cellular oxidation, [Ca2+]i, or endothelial barrier function. These results suggest that certain PCBs may play a role in the development of atherosclerosis by causing endothelial cell dysfunction and a decrease in the barrier function of the vascular endothelium. It is possible that interaction of PCBs with the Ah receptor and activation of the cytochrome P450 1A subfamily are involved in this pathology.
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Affiliation(s)
- M Toborek
- Department of Nutrition and Food Science, University of Kentucky, Lexington 40506-0054, USA
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