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1.
Prevention of ischemia-induced cardiac Sudden death by n−3 polyunsaturated fatty acids in dogs 总被引:8,自引:0,他引:8
The objective of this study was to obtain functional information associated with the prevention by n−3 polyunsaturated fatty
acids (PUFA) of ischemia-induced fatal cardiac ventricular arrhythmias in the intact, conscious, exercising dog. Thirteen
dogs suceptible to ischemia-induced ventricular fibrillation were prepared surgically by ligation of their anterior descending
left coronary artery and placement of an inflatable cuff around their left circumflex artery. After 4 wk of recovery, exercise-plus-ischemia
tests were performed without and then with an intravenous infusion of an emulsion of free n−3 PUFA just prior to occluding
the left circumflex artery while the animals were running on a treadmill. One week later the exercise-plus-ischemia test was
repeated but with a control infusion replacing the emulsion of n−3 PUFA. The infusion of the free n−3 PUFA in quantities of
1.0 to 10 g prevented ventricular fibrillation in 10 of the 13 dogs tested (P<0.005), apparently without esterification of the PUFA into membrane phospholipids. The antiarrhythmic effect of the n−3 PUFA
was associated with slowing of the heart rate, shortening of the QT-interval (electrical action potential duration), reduction
of left ventricular systolic pressure, and prolongation of the electrocardiographic atrial-ventricular conduction time (P-R
interval). These effects are comparable with those we have reported in studies with cultured neonatal rat cardiac myocytes. 相似文献
2.
P. Pauletto M. Puato M. T. Angeli A. C. Pessina A. Munhambo G. Bittolo-Bon C. Galli 《Lipids》1996,31(1):S309-S312
Major risk factors for coronary heart disease were assessed in two populations of Tanzania, one on a fish diet (FD) living
along the coast of Lake Nyasa, and the other, mainly on a vegetarian diet (VD), living in a farming area. Lower blood pressure
values were found in the FD subjects (n=618) vs. VD (n=618) (systolic blood pressure, SBP, 120±15 vs. 135±20,P<0.01; diastolic blood pressure, DBP, 70±9 vs. 78±11,P<0.01, respectively). In an FD subgroup (n=61), total cholesterol (TC) (122 vs. 136 mg/dL,P<0.01); triglycerides (TG) (82 vs. 105 mg/dL,P<0.01); and lipoprotein (a) [Lp(a)] (19.9±18.4 vs. 32.3±22.4,P<0.001) were lower than in a VD subgroup (n=55). Serum fatty acids (FA) in the FD subgroup were as follows: eicosapentaenoic
acid (EPA) (20∶5) 2.48 vs. 0.72%, docosahexaenoic acid (DHA) (22∶6) 5.93 vs. 1.49%, vs. the VD, respectively. Arachidonic
acid (AA) (20∶4n-6) also was higher in the FD vs. the VD group (9.85 vs. 8.30%,P<0.05), whereas 18∶2n-6 was about double (23.97 and 14.85%) in VD vs. FD. The peculiar serum FA pattern in FD reflected the
FA of dietary fish. In fact, in four main species of lake fish, DHA was 8–19%, higher than EPA (1.8–4.2%), in contrast with
the situation in cold-water fish, and AA was 5.8–8%, higher than in cold-water fish. The data, obtained in populations strictly
on natural, unprocessed, low-fat diets, show that a diet based on freshwater fish results in lower BP, serum TC, TG, and Lp(a),
and suggests that serum AA is not reduced when the major dietary n-3 is DHA rather than EPA. 相似文献
3.
Alessandri JM Extier A Langelier B Perruchot MH Heberden C Guesnet P Lavialle M 《Lipids》2008,43(1):19-28
Whether neurosteroids regulate the synthesis of long chain polyunsaturated fatty acids in brain cells is unknown. We examined
the influence of 17-β-estradiol (E2) on the capacity of SH-SY5Y cells supplemented with α-linolenic acid (ALA), to produce
eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). Cells were incubated for 24 or 72 h
with ALA added alone or in combination with E2 (ALA + E2). Fatty acids were analyzed by gas chromatography of ethanolamine
glycerophospholipids (EtnGpl) and phosphatidylcholine (PtdCho). Incubation for 24 h with ALA alone increased EPA and DPA in
EtnGpl, by 330 and 430% compared to controls (P < 0.001) and DHA by only 10% (P < 0.05). Although DHA increased by 30% (P < 0.001) in ALA + E2-treated cells, the difference between the ALA and ALA + E2 treatments were not significant after 24 h
(Anova-1, Fisher’s test). After 72 h, EPA, DPA and DHA further increased in EtnGpl and PtdCho of cells supplemented with ALA
or ALA + E2. Incubation for 72 h with ALA + E2 specifically increased EPA (+34% in EtnGpl, P < 0.001) and DPA (+15%, P < 0.001) compared to ALA alone. Thus, SH-SY5Y cells produced membrane EPA, DPA and DHA from supplemental ALA. The formation
of DHA was limited, even in the presence of E2. E2 significantly favored EPA and DPA production in cells grown for 72 h. Enhanced
synthesis of ALA-elongation products in neuroblastoma cells treated with E2 supports the hypothesis that neurosteroids could
modulate the metabolism of PUFA. 相似文献
4.
Aiko Kawashima Ikuyo Tsukamoto Tomoko Koyabu Yasuko Murakami Takayo Kawakami Naoko Kakibuchi Kouichi Takaguchi Keiji Kita Misako Okita 《Lipids》2008,43(4):325-333
Eicosapentaenoic acid (EPA) (1.8 g/day) was administered to 12 chronic hepatitis C patients receiving combination therapy
of pegylated interferon (PEG-IFN) α-2b and ribavirin for 48 weeks (EPA group). Twelve patients were not administered EPA (control
group). All patients also received vitamin E and C (300, 600 mg/day, respectively) during the therapy. Serum alanine aminotransferase
improved to a normal level in 8 of 12 patients from the EPA group and 6 of 12 patients from the control group after 12 weeks.
Lymphocyte counts decreased significantly after 8 weeks in the control group, but not the EPA group. T-helper (Th) 1 decreased
after 4 weeks in the control group, but not in the EPA group (two-way ANOVA; P < 0.05). Th1/Th2 ratios were elevated in 9 of 12 patients in the EPA group, and 3 out of 12 in the control group (P < 0.05) after 8 weeks. After 12 weeks, the arachidonic acid/EPA molar ratio of erythrocyte membrane phospholipid correlated
negatively with the leukocyte count (n = 24, r = −0.439, P < 0.05) and the neutrophil count (n = 24, r = −0.671, P < 0.02). The hemoglobin level improved after 48 weeks compared with 24 weeks in only the EPA group. These findings suggest
that EPA supplementation may be useful in therapy for chronic hepatitis C. 相似文献
5.
Plant sources of omega-3 fatty acids (FA) are needed that can materially raise tissue levels of long-chain omega-3 FA [i.e.,
eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 20:6n-3)]. Stearidonic acid (SDA; 18:4n-3) is the delta-6
desaturase product of alpha-linolenic acid (ALA; 18:3n-3), and when fed to humans, increases red blood cell (RBC) content
of EPA to a greater extent than does ALA. This study was undertaken to determine the dose-dependence and time course of the
increase in the EPA and DHA content of the heart and RBC in dogs. Adult male Beagles were fed 21, 64, or 193 mg/kg of SDA
in in their food daily for up to 12 weeks. Positive and negative controls were given EPA (43 mg/kg) or high oleic acid sunflower
oil, respectively. The baseline EPA content of RBC was 0.38 ± 0.03% which increased (P < 0.01) in a dose-dependent manner, with the high dose of SDA and EPA achieving levels of 1.33 ± 0.26 and 1.55. ± 0.28%,
respectively. In the heart, the content of EPA rose from 0.06 ± 0.01 to 1.24 ± 0.22% in the EPA group and to 0.81 ± 0.32%
in the high SDA group (both P < 0.01). In both tissues, DHA did not change. Compared to dietary EPA, SDA was 20–23% as efficient in raising tissue EPA
levels. In conclusion, SDA supplementation increased the EPA content of RBC and heart and may have utility as a plant-based
source of omega-3 FA. 相似文献
6.
Dietary Fatty Acids Differentially Regulate Secretion of Adiponectin and Interleukin‐6 in Primary Canine Adipose Tissue Culture 下载免费PDF全文
The aim of this study was to determine the effect of n3 polyunsaturated fatty acids (PUFA) on canine adipose tissue secretion of adiponectin, interleukin‐6 (IL6), and tumor necrosis factor‐α (TNFα). Subcutaneous and omental visceral adipose tissue samples were collected from 16 healthy intact female dogs. Concentrations of adiponectin were measured in mature adipocyte cultures, and concentrations of IL6 and TNFα were measured in undifferentiated stromovascular cell (SVC) cultures following treatment with eicosapentaenic acid (EPA, 20:5n‐3), arachidonic acid (ARA, 20:4n‐6), or palmitic acid (PAM, 16:0) at 25, 50, or 100 μM. Secretion of adiponectin from mature adipocytes was higher (p < 0.001) following EPA treatment at 50 μM compared to control in subcutaneous tissue, and higher following EPA treatment compared to PAM treatment at 25 μM in both subcutaneous (p < 0.001) and visceral tissues (p = 0.010). Secretion of IL6 from SVC derived from subcutaneous tissue was lower following EPA treatment and higher following PAM treatment compared to control both at 50 μM (p = 0.001 and p = 0.041, respectively) and 100 μM (p = 0.013 and p < 0.001, respectively). These findings of stimulation of adiponectin secretion and inhibition of IL6 secretion by EPA, and stimulation of IL6 secretion by PAM, are consistent with findings of increased circulating concentrations of adiponectin and decreased circulating concentration of IL6 in dogs supplemented with dietary fish oil, and show that the effect of fish oil on circulating concentrations of adiponectin and IL6 is, at least partially, the result of local effects of EPA and PAM on adipose tissue. 相似文献
7.
Normal, healthy male volunteers (n=6) were fed diets [high docosahexaenoic acid-DHA] containing 6 g/d of DHA for 90 d. The stabilization (low-DHA) diet contained
less than 50 mg/d of DHA. A control group (n=4) remained on the low-DHA diet for the duration of the study (120 d). Blood samples were drawn on study days 30 (end of
the stabilization period), 75 (midpoint of the intervention period), and 120 (end of the intervention period). Adipose tissue
(AT) samples were taken on days 30 and 120. The plasma cholesterol (C), low density lipoprotein (LDL)-C and apolipoproteins
(apo) [Al, B, and lipoprotein (a)] were unchanged after 90 d, but the triglycerides (TAG) were reduced from a mean value of
76.67±24.32 to 63.83±16.99 mg/dL (n=6, P<0.007 using a paired t-test) and the high density lipoprotein (HDL)-C increased from 34.83±4.38 mg/dL to 37.83±3.32 mg/dL (n=6, P<0.017 using a paired t-test). The control group showed no significant reduction in plasma TAG levels. Apo-E, however, showed a marked increase in
the volunteers’ plasma after 90 d on the high-DHA diet, from 7.06±4.47 mg/dL on study day 30 to 12.01±4.96 mg/dL on study
day 120 (P<0.002 using a paired t-test). The control subjects showed no significant change in the apo-E in their plasma (8.46±2.90 on day 30 vs. 8.59±2.97
on day 120). The weight percentage of plasma DHA rose from 1.83±0.22 to 8.12±0.76 after 90 d on the high-DHA diet. Although
these volunteers were eating a diet free of eicosapentaenoic acid (EPA), plasma EPA levels rose from 0.38±0.05 to 3.39±0.52
(wt%) after consuming the high-DHA diet. The fatty acid composition of plasma lipid fractions—cholesterol esters, TAG, and
phospholipid—showed marked similarity in the enrichment of DHA, about 10%, after the subjects consumed the high-DHA diet.
The DHA content of these plasma lipid fractions varied from less than 1% (TAG) to 3.5% (phospholipids) at baseline, study
day 30. EPA also increased in all plasma lipid fractions after the subjects consumed the high-DHA diet. There were no changes
in the plasma DHA or EPA levels in the control group. Consumption of DHA also caused an increase in AT levels of DHA, from
0.10±0.02 to 0.31±0.07 (wt%) (n=6, P<0.001 using a paired t-test), but the amount of EPA in their AT did not change. Thus, dietary DHA will lower plasma TAG without EPA, and DHA is
retroconverted to EPA in significant amounts. Dietary DHA appears to enhance apo-E synthesis in the liver. It appears that
DHA can be a safe and perhaps beneficial supplement to human diets. 相似文献
8.
The aim of this study was to investigate the functional consequences in vivo of adapting the rat exocrine pancreas to different dietary fats. Weanling rats were fed diets containing 10 wt% virgin olive
oil or sunflower oil for 8 wk. We then examined resting and cholecystokinin-octapeptide (CCK-8)-stimulated pancreatic secretion
in the anesthetized animals. To confirm a direct influence of the type of fat upon the gland, the FA composition of pancreatic
membranes as well as tissue protein and amylase content were determined in separate rats. The membrane FA profile was profoundly
altered by the diets, reflecting the type of dietary fat given, although this was not paralleled by variations in the pancreatic
content of protein or amylase. Nevertheless, dietary intake of oils evoked different effects on in vivo secretory activity. Resting flow rate and amylase output were significantly (P<0.05) enhanced by sunflower oil feeding. Time course changes in response to CCK-8 infusion also showed a different pattern
in each group. Secretion of fluid, protein, and amylase increased markedly in all animals, reaching a maximum within 20–40
min of infusion that was followed by a dramatic decline in both groups. In the sunflower oil group, this resulted in values
reaching the resting level as soon as 60 min after CCK-8 infusion was begun. However, after the initial decline, olive oil
group values showed a prolonged plateau elevation above the baseline (P<0.05) that was maintained for at least the infusion time. In addition, a positive correlation between flow rate and both
protein concentration and amylase activity existed in the olive oil group, but not in the sunflower oil group. The precise
mechanism by which these effects are produced remains to be elucidated. 相似文献
9.
Low density lipoprotein (LDL) plasma concentration is increased in the elderly. In this group, the incidence of coronary artery
disease (CAD) is greater and LDL remains an important risk factor for CAD development. In this study, the plasma kinetics
of a cholesterol-rich emulsion that binds to LDL receptors was studied in 10-subject groups of the elderly (70±4 yr), middle-aged
(42±5 yr) and young (23±2 yr). All were normolipidemic, nonobese, nondiabetic subjects who did not have CAD. The emulsion
was labeled with 14C-cholesteryl oleate and injected intravenously into the subjects. Blood samples were drawn at regular intervals over 24 h
to determine the plasma decay curve of the emulsion radioactive label and to estimate its plasma fractional clearance rate
(FCR, in h−1). FCR of the emulsion label was smaller in elderly compared to young subjects (0.032±0.035 and 0.071±0.049 h−1, respectively; mean±SD, P<0.05). FCR of the middle-aged subjects (0.050±0.071 h−1) was intermediate between the values of the elderly and young subjects, although not statistically different from them. A
negative correlation was found between the emulsion FCR and subjects’ age (r=−0.47, P=0.008). We conclude that aging is accompanied by progressively diminished clearance of the emulsion cholesterol esters and,
by analogy, of the native LDL. 相似文献
10.
Isabel S. Chen Truc Le Satchithanandam Subramanian Marie M. Cassidy Alan J. Sheppard George V. Vahouny 《Lipids》1987,22(5):318-321
Rat mesenteric lymph chylomicrons containing triglycerides enriched with either [14C]oleic acid (OA) or [14C]-eicosapentaenoic acid (EPA) were prepared by ultracentrifugation of lymph samples collected for 6 hr after a single duodenal
infusion of an emulsion containing either fatty acid. These chylomicrons were injected into the jugular vein of recipient
rats and, at various time intervals, blood was drawn and serum was assayed for radioactivity. In separate animals, serum lipoprotein
fractions were separated by ultracentrifugation, and the redistribution of labeled fatty acid among circulating lipoproteins
was determined by liquid scintillation spectrometry. When the early disappearance rates (10 min) of either total serum radioactivity
or specifically the chylomicron fraction were compared, there were no differences between the groups receiving OA-or EPA-enriched
chylomicrons. However, disappearance rates of EPA-enriched chylomicrons were slower than those of OA-enriched chylomicrons
from 25 to 90 min. The small but significant differences in the disappearance rates for the longer time periods cannot be
ascertained without further studies. At 5 min after injection of either type of chylomicron, the d<1.006 g/ml lipoprotein
fraction of serum chylomicrons and very low density lipoproteins contained almost 90% of the original radioactivity. By 240
min, when less than 2% of the radioactivity remained, this radioactivity in the d<1.006 g/ml fraction was 43–46%, with concomitant
increases in the low and high density lipoprotein fractions and in the lipoprotein-free serum.
Deceased. 相似文献
11.
As meat is a rich source of the omega-3 fatty acid docosapentaenoic acid (DPA) and Australians consume six times more meat than fish, investigation of the potential health benefit of DPA is warranted. The aims were to compare the effects of seal oil supplementation with fish oil, on measures of plasma lipids and blood pressure in hypertriglyceridaemic subjects. Forty-eight volunteers were recruited from the Wollongong community and were randomly allocated to one of three groups either receiving 1 g/day of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) using one of three oils: seal oil capsules (340 mg eicosapentaenoic acid (EPA), 230 mg DPA, 450 mg DHA), fish oil capsules (210 mg EPA, 30 mg DPA, 810 mg DHA) or placebo capsules (containing sunola oil) for 6 weeks. Plasma triglycerides remained unchanged in the placebo group, whilst reductions of 7 and 14% (P < 0.05) were seen in the fish oil and seal oil groups respectively. Systolic blood pressure improved by 8 and 5 mmHg with seal oil and fish oil respectively (P < 0.05). The mean arterial pressure was significantly lower after seal oil supplementation (P < 0.005) compared with the placebo group. These results indicate that seal oil is as effective as fish oil in lowering plasma triglycerides and blood pressure. 相似文献
12.
Telle-Hansen VH Larsen LN Høstmark AT Molin M Dahl L Almendingen K Ulven SM 《Lipids》2012,47(2):151-160
Intake of fish and omega-3 (n-3) fatty acids is associated with a reduced concentration of plasma triacylglycerols (TAG) but
the mechanisms are not fully clarified. Stearoyl-CoA desaturase-1 (SCD1) activity, governing TAG synthesis, is affected by
n-3 fatty acids. Peripheral blood mononuclear cells (PBMC) display expression of genes involved in lipid metabolism. The aim
of the present study was to estimate whether intake of lean and fatty fish would influence n-3 fatty acids composition in
plasma phospholipids (PL), serum TAG, 18:1n-9/18:0 ratio in plasma PL, as well as PBMC gene expression of SCD1 and fatty acid
synthase (FAS). Healthy males and females (n = 30), aged 20–40, consumed either 150 g of cod, salmon, or potato (control) daily for 15 days. During intervention docosahexaenoic
acid (DHA, 22:6n-3) increased in the cod group (P < 0.05), while TAG concentration decreased (P < 0.05). In the salmon group both eicosapentaenoic acid (EPA, 20:5n-3) and DHA increased (P < 0.05) whereas TAG concentration and the 18:1n-9/18:0 ratio decreased (P < 0.05). Reduction of the 18:1n-9/18:0 ratio was associated with a corresponding lowering of TAG (P < 0.05) and an increase in EPA and DHA (P < 0.05). The mRNA levels of SCD1 and FAS in PBMC were not significantly altered after intake of cod or salmon when compared
with the control group. In conclusion, both lean and fatty fish may lower TAG, possibly by reducing the 18:1n-9/18:0 ratio
related to allosteric inhibition of SCD1 activity, rather than by influencing the synthesis of enzyme protein. 相似文献
13.
Response Surface Analysis and Modeling of Flaxseed Oil Yield in Supercritical Carbon Dioxide 总被引:1,自引:0,他引:1
Sami Gökhan Özkal 《Journal of the American Oil Chemists' Society》2009,86(11):1129-1135
Supercritical fluid extraction of flaxseed oil with carbon dioxide was performed. Effects of particle size, pressure, temperature
and the flow rate of supercritical carbon dioxide (SC-CO2) were investigated. Response surface methodology was used to determine the effects of pressure (30–50 MPa), temperature (50–70 °C)
and SC-CO2 flow rate (2–4 g/min) on flaxseed oil yield in SC-CO2. The oil yield was represented by a second order response surface equation (R
2 = 0.993) using the Box-Behnken design of experiments. The oil yield increased significantly with increasing pressure (p < 0.01), temperature (p < 0.05) and SC-CO2 flow rate (p < 0.01). The maximum oil yield from the response surface equation was predicted as 0.267 g/g flaxseed for 15 min extraction
of 5 g flaxseed particles (particle diameter <0.850 mm) at 50 MPa pressure and 70 °C temperature, with 4 g/min solvent flow
rate. Total extraction time at these conditions was predicted as 22 min. 相似文献
14.
Effect of low-to-moderate amounts of dietary fish oil on neutrophil lipid composition and function 总被引:8,自引:0,他引:8
Although essential to host defense, neutrophils are also involved in numerous inflammatory disorders including rheumatoid
arthritis. Dietary supplementation with relatively large amounts of fish oil [containing >2.6 g eicosapentaenoic acid (EPA)
plus 1.4 g docosahexaenoic acid (DHA) per day] can attenuate neutrophil functions such as chemotaxis and superoxide radical
production. In this study, the effects of more moderate supplementation with fish oil on neutrophil lipid composition and
function were investigated. The rationale for using lower supplementary doses of fish oil was to avoid adverse gastrointestinal
problems, which have been observed at high supplementary concentrations of fish oil. Healthy male volunteers aged <40 yr were
randomly assigned to consume one of six dietary supplements daily for 12 wk (n=8 per treatment group). The dietary supplements included four different concentrations of fish oil (the most concentrated
fish oil provided 0.58 g EPA plus 1.67 g DHA per day), linseed oil, and a placebo oil. The percentages of EPA and DHA increased
(both P<0.05) in neutrophil phospholipids in a dose-dependent manner after 4 wk of supplementation with the three most concentrated
fish oil supplements. No further increases in EPA or DHA levels were observed after 4 wk. The percentage of arachidonic acid
in neutrophil phospholipids decreased (P<0.05) after 12 wk supplementation with the linseed oil supplement or the two most concentrated fish oil supplements. There
were no significant changes in N-formyl-met-leu-phe-induced chemotaxis and superoxide radical production following the dietary supplementations. In conclusion,
low-to-moderate amounts of dietary fish oil can be used to manipulate neutrophil fatty acid composition. However, this may
not be accompanied by modulation of neutrophil functions such as chemotaxis and superoxide radical production. 相似文献
15.
It has been reported that apoptosis is a significant contributor to myocardial cell death as a result of reperfusion injury.
However, whether the extent of cardiomyocyte apoptosis following ischemia and reperfusion varies in different pathophysiological
backgrounds is still uncertain. In this study, we examined whether hypercholesterolemia increases the extent of myocardial
reperfusion injury by aggravating cardiomyocyte apoptosis and the effects of hypercholesterolemia on the expression of Bcl-2
and Bax proteins and the activation of caspase-3. Twenty-eight male New Zealand white rabbits were fed standard chow (control,
n=14) or chow supplemented with 1% cholesterol (hypercholesterolemic, n=14) for 8 wk. Anesthetized rabbits were then subjected to 30 min of left circumflex artery occlusion followed by 4 h of reperfusion.
Apoptosis was identified as “DNA ladders” by gel electrophoresis and confirmed histologically using the terminal deoxynucleotidyl
transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. The infarct size (% of risk region) was significantly greater
in hypercholesterolemic rabbits than in controls (39±6 vs. 23±2%, P=0.02). Very few TUNEL-positive cardiomyocytes could be identified in the nonischemic regions in both groups, consistent with
an absence of DNA laddering. In contrast, TUNEL-positive cardiomyocytes were significantly displayed in the ischemic, nonnecrotic
myocardium, and DNA ladder occurred in all animals. The percentage of TUNEL-positive cardiomyocytes in the ischemic nonnecrotic
myocardium was significantly higher in hypercholesterolemic rabbits compared with controls (40±5 vs. 17±1%, P<0.001). Western blot analysis showed that, in the nonischemic myocardium, hypercholesterolemic rabbits exhibited an approximately
50% increase in the expression of Bcl-2 (P<0.05), but not Bax, than control rabbit. However, compared with controls, hypercholesterolemic rabbits exhibited a more pronounced
decrease in the expression of Bcl-2 (42±4 vs. 26±2%, P<0.01) and a similar extent of increase in the expression of Bax in the ischemic myocardium. Furthermore, hypercholesterolemic
rabbits were associated with a markedly increased activation of caspase-3 within the ischemic myocardium compared to control
rabbits. This study demonstrates that although hypercholesterolemia is associated with an increased myocardial Bcl-2/Bax ratio
at baseline, it still significantly exacerbates cardiac reperfusion injury, not only by increasing the infarct size but also
by increasing the extent of cardiomyocyte apoptosis. 相似文献
16.
Elvevoll EO Barstad H Breimo ES Brox J Eilertsen KE Lund T Olsen JO Osterud B 《Lipids》2006,41(12):1109-1114
This work was undertaken to study the impact of the source of n−3 FA on their incorporation in serum, on blood lipid composition,
and on cellular activation. A clinical trial comprising 71 volunteers, divided into five groups, was performed. Three groups
were given 400 g smoked salmon (n=14), cooked salmon (n=15), or cooked cod (n=13) per week for 8 wk. A fourth group was given 15 mL/d of cod liver oil (CLO) (n=15), and a fifth group served as control (n=14) without supplementation. The serum content of EPA and DHA before and after intervention revealed a higher rise in EPA
and DHA in the cooked salmon group (129% rise in EPA and 45% rise in DHA) as compared with CLO (106 and 25%, respectively)
despite an intake of EPA and DHA in the CLO group of 3.0 g/d compared with 1.2 g/d in the cooked salmon group. No significant
changes were observed in blood lipids, fibrinogen, fibrinolysis, or lipopolysaccharide (LPS)-induced tissue factor (TF) activity,
tumor necrosis factor-α (TNFα), interleukin-8 (IL-8), leukotriene B4 (LTB4), and thromboxane B2 (TxB2) in whole blood. EPA and DHA were negatively correlated with LPS-induced TNFα, IL-8, LTB4, TxB2, and TF in whole blood. In conclusion, fish consumption is more effective in increasing serum EPA and DHA than supplementing
the diet with fish oil. Since the n−3 FA are predominantly in TAG in fish as well as CLO, it is suggested that the larger
uptake from fish than CLO is due to differences in physiochemical structure of the lipids. 相似文献
17.
Robert E. Goldstein Giora Z. Feuerstein Linda M. Bradley Joseph J. Stambouly Francisco R. M. Laurindo Nancy J. Davenport 《Lipids》1991,26(12):1250-1256
Sudden release of platelet-activating factor (PAF) into the circulation can cause hypotension, tachycardia, and circulatory
collapse. To further examine this response, we performed detailed studies of cardiovascular function after PAF administration
to young domestic pigs and newborn piglets. Our results indicate that circulatory dysfunction after PAF reflects severe constriction
of pulmonary resistance vessels and consequent acute right ventricular failure. Although PAF-induced coronary artery constriction
and contractile depression may be complicating problems, left ventricular underperfusion and dysfunction after PAF are mainly
the result of systemic arterial hypotension and diminished left ventricular filling. The adverse hemodynamic effects of PAF
are accompanied by substantial release of thromboxane A2 (TxA2). These effects are mimicked by the TxA2 agonist U-46619 and partially blocked by specific and nonspecific inhibitors of TxA2 synthesis (OKY-046 and indomethacin). Even more potent blockade of PAF action is exerted by the TxA2 receptor blocker, SQ 29,548. Taken together, these findings indicate that severe pulmonary vascular constriction and hemodynamic
collapse soon after intravenous PAF are at least partially mediated by PAF-induced TxA2 release.
Tachyphylaxis to PAF influence has been observed in studies of leukocyte and platelet function. We hypothesized that tachyphylaxis
to PAF might also occur in our studies of constrictor responses in pulmonary vessels. Recently, we have examined the capacity
of PAF to produce sustained pulmonary vasoconstriction in openchested, anesthetized newborn piglets. Infusions sufficient
to produce 100% increase in mean pulmonary artery pressure after 3 min showed no loss of efficacy when sustained for 30 min.
The same was true for infusions of U-46619. Thus, the pulmonary vasoconstrictor influence of PAF or U-46619 is not readily
diminished by tachyphylaxis. These findings favor the viewpoint that PAF or TxA2 release during inflammatory processes could have prolonged adverse actions on pulmonary and systemic circulations.
Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl
Ether Lipids, Tokyo, Japan, May 1989.
The opinions or assertions contained here are those of the authors. They do not reflect the views of the Department of Defense
or the Uniformed Services University of the Health Sciences. The experiments reported here were conducted according to the
principles set forth in the “Guide for the Care and Use of Laboratory Animals,” Institute of Laboratory Animal Resources,
U.S. Department of Health and Human Services (NIH Publ. 85-23, 1985). 相似文献
18.
The effect of dietary docosahexaenoic acid (DHA) in the absence of eicosapentaenoic acid (EPA) has been studied infrequently
in humans under controlled conditions. This 120-d study followed healthy, adult male volunteers who lived in the metabolic
research unit (MRU) of the Western Human Nutrition Research Center for the entire study. The basal (low-DHA) diet consisted
of natural foods (30 en% fat, 15 en% protein, and 55 en% carbohydrate), containing <50 mg/d of DHA, and met the recommended
daily intake for all essential nutrients. The high-DHA (intervention) diet was similar except that 6 g/d of DHA in the form
of a triglyceride containing 40% DHA replaced an equal amount of safflower oil in the basal diet. The subjects (ages 20 to
39) were within −10 to +20% of ideal body weight, nonsmoking, and not allowed alcohol in the MRU. Their exercise level was
constant, and their body weights were maintained within 2% of entry level. They were initially fed the low-DHA diet for 30
d. On day 31, six subjects (intervention, group A) were placed on the high-DHA diet; the other four subjects (controls, group
B) remained on the low-DHA diet. Platelet aggregation in platelet-rich plasma was determined using ADP, collagen, and arachidonic
acid. No statistical differences could be detected between the amount of agonist required to produce 50% aggregation of platelet-rich
plasma before and after the subjects consumed the high-DHA diet. The prothrombin time, activated partial thromboplastin time,
and the antithrombin-III levels in the subjects were determined, and, again, there were no statistically significant differences
in these three parameters when their values were compared before and after the subjects consumed the high-DHA diet. In addition,
the in vivo bleeding times did not show any significant difference before and after the subjects consumed the high-DHA diet (9.4 ±3.1
min before and 8.0±3.4 min after). Platelets from the volunteers exhibited more than a threefold increase in their DHA content
from 1.54±0.16 to 5.48±1.21 (wt%) during the DHA feeding period. The EPA content of the subjects’ platelets increased from
0.34±0.12 to 2.67±0.91 (wt%) during the high-DHA diet despite the absence of EPA in the subjects’ diets. The results from
this study on blood clotting parameters and in vitro platelet aggregation suggest that adding 6 g/d of dietary DHA for 90 d to a typical Western diet containing less than 50
mg/d of DHA produces no observable physiological changes in blood coagulation, platelet function, or thrombotic tendencies
in healthy, adult males. 相似文献
19.
Human chylomicron triglyceride (TG) kinetics has been difficult to determine directly owing to technical limitations. This
report describes a new method for studying chylomicron metabolism. Healthy volunteers (n=10) sipped a drink providing 175 mg fat·kg−1·h−1 for 7.5 h to produce a steady-state chylomicronemia. A commercial 10% intravenous lipid emulsion was labeled with [3H]triolein, purified by high-performance liquid chromatography, and sterilized. A trace amount of labeled emulsion was injected
intravenously 30 min before (i.e., in the fasting state) and 5, 6, and 7 h after sipping began (i.e., triplicate determinations
in the fed state). Chylomicron half-lives were calculated from the monoexponential decay curves, and apparent distribution
volumes were estimated by back-extrapolation to time zero. Plasma and estimated chylomicron TG concentrations increased from
89±13 and 0.8±0.3 to 263±43 and 91±39 mg/dL (mean±SEM), respectively, with feeding. Tracer-determined chylomicron TG half-lives
were 5.34±0.58 and 6.51±0.58 min during the fasting and fed states, respectively (P<0.01). The apparent distribution volume during the fasting state was 24% greater than plasma volume (4515±308 vs. 3630±78
mL, P<0.02), consistent with significant margination of lipid emulsion particles to endothelial binding sites. Margination was
reduced during the fed state, suggesting that native chylomicrons competed with lipid emulsion particles for endothelial lipoprotein
lipase. The results indicate that a radiolabeled commercial lipid emulsion is metabolized in a fashion similar to native chylomicron
TG, and thus can be used to study chylomicron TG kinetics. 相似文献
20.
Tomohito Hamazaki Masaharu Urakaze Saburo Yano Yasuji Soda Akira Miyamoto Kohji Kubota Fumio Ibuki 《Lipids》1987,22(12):1031-1034
An injectable emulsion of docosahexaenoic acid (DHA) was prepared. One hundred ml of the emulsion contained 3 g of 93%-pure
1,2,3-tridocosahexaenoylglycerol (DHA-TG), 1.2 g of 93%-pure 2-docosahexaenoyl-phosphatidylcholine as an emulsifier and 2.5
g of glycerol. Thirty ml of the emulsion of DHA-TG was injected into three rabbits on days 1 and 4 of the study. Blood was
taken on day 0, on day 4 just before the second injection and on day 7. The percentage of DHA in the total phospholipid fraction
of platelets increased from 0.46% (day 0) to 1.88% (day 4, p<0.05) and 3.66% (day 7; p<0.02 vs day 0). The percentage of eicosapentaenoic
acid (EPA) increased from 0.46% (day 0) to 1.03% (day 4, p<0.02) and 1.63% (day 7: p<0.05 vs day 0). The percentage of arachidonic
acid (AA) decreased from 9.45% (day 0) to 4.31% (day 4, p<0.05) and 6.68% (day 7; p<0.02 vs day 0). The percentage of DHA
in the total phospholipid fraction of erythrocyte membranes increased from 0.23% (day 0) to 0.91% (day 4, p<0.05) and 1.52%
(day 7; p<0.005 vs day 0); that of EPA increased from 0.21% (day 0) to 0.34% (day 4, p<0.005%) and 0.52% (day 7, p<0.01 vs
day 0); that of AA was unchanged. Blood lipids were the same before and after the two injections of the emulsion, except that
free fatty acids decreased markedly from 0.32 to 0.06 mEq/1 (p<0.02). On day 8, free AA (2 mg/kg) was injected into ear veins
of the three treated rabbits and of four control rabbits (not treated with DHA-TG). All the control rabbits died a few minutes
after the AA injection, but none of the DHA-treated rabbits died after AA injection (p<0.01). An emulsion of DHA-TG may be
useful for patients having immediate risk of thrombosis or for those who need DHA but cannot take it orally. 相似文献