Individual effects of dietary EPA and DHA on the functioning of the isolated working rat heart

1998 ◽  
Vol 76 (7-8) ◽  
pp. 728-736 ◽  
Author(s):  
J -P Sergiel ◽  
L Martine ◽  
D Raederstorff ◽  
A Grynberg ◽  
L Demaison

The aim of this study was to evaluate the effects of dietary pure eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the physiology of the heart in normoxic conditions and during postischemic reperfusion. These effects were compared with those of dietary n-6 polyunsaturated fatty acids (PUFA). Rats were fed a diet containing either sunflower seed oil (75 g·kg-1, SSO group), or a mixture of EPA (20:5 n-3) ethyl ester and SSO (10:90, EPA group), or a mixture of DHA (22:6 n-3) ethyl ester and SSO (10:90, DHA group), or a mixture of EPA + DHA ethyl esters and SSO (4.2:5.8:90, e+D group) for 6 weeks. The hearts were then perfused according to the working mode. The perfusion was maintained either in normoxic conditions or stopped for 17 min (global zero-flow ischemia) and restored for 33 min (reperfusion). The aortic and coronary flows, aortic developed pressure, and electrocardiogram were continuously monitored. When rats were fed a diet containing either EPA and (or) DHA, the n-6/n-3 PUFA ratio of cardiac phospholipids decreased. The proportion of arachidonic acid was reduced more with DHA than dietary EPA. In the EPA group, the percentage of DHA was lower than in the DHA group, but the percentage of EPA and docosapentaenoic acid (22:5 n-3) was higher. These changes in membrane fatty acid composition altered the cardiac function. In normoxic conditions, the coronary flow was higher in the SSO group than in the DHA and EPA groups. The heart rate was lower in the DHA and e+D groups than in the EPA and SSO groups. The aortic flow, cardiac output, and aortic developed pressure were not affected. During postischemic reperfusion, the recovery of aortic flow, coronary flow, and aortic developed pressure was similar in the four groups. A slightly improved recovery of cardiac function was noticed in the EPA group, but the difference was not significant. Feeding rats 5% fish oil + 5% SSO instead of 10% SSO for 8 weeks increased the incorporation of EPA in cardiac phospholipids and favored the recovery (+120%) of aortic flow during postischemic reperfusion. In conclusion, the beneficial effect of dietary fish oil on the recovery of cardiac pump activity during reperfusion was not observed with DHA or EPA alone. It appears to be positively related to the accumulation of EPA in membrane phospholipids. The dietary conditions favouring EPA accumulation remain to be determined.Key words: dietary polyunsaturated fatty acids, myocardial ischemia, reperfusion.

1996 ◽  
Vol 271 (4) ◽  
pp. H1483-H1490 ◽  
Author(s):  
K. E. Anderson ◽  
X. J. Du ◽  
A. J. Sinclair ◽  
E. A. Woodcock ◽  
A. M. Dart

Dietary enrichment with fish oil-derived n-3 polyunsaturated fatty acids has been shown to suppress the arrhythmias that occur during postischemic reperfusion. We have recently implicated a rapid release of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] during postischemic reperfusion in the generation of these arrhythmias. The effects of dietary supplementation with fish oil on both cardiac Ins(1,4,5)P3 and arrhythmogenic responses to reperfusion were therefore investigated in perfused rat hearts. Comparisons were made with control and n-6 polyunsaturated or saturated fat-supplemented diets. In control hearts, reperfusion increased Ins(1,4,5)P3 levels [from 9 +/- 2 at 20 min ischemia to 26 +/- 3 counts per minute (cpm)/mg protein with 2 min of reperfusion] and produced a high incidence of ventricular tachycardia (92% VT) and ventricular fibrillation (85% VF). Dietary fish oil supplementation, which increased composition of n-3 fatty acids in myocardial membrane phospholipids, prevented the reperfusion-induced rise in Ins(1,4,5)P3 (11 +/- 1 at 20 min ischemia and 12 +/- 2 cpm/mg protein after 2-min reperfusion) and significantly suppressed reperfusion arrhythmias (38% VT, 13% VF; P < 0.01 vs. control group). Thus the inhibition of reperfusion-induced rises in Ins(1,4,5)P3 by n-3 polyunsaturated fatty acids after dietary fish oil supplementation provides a possible mechanism for the inhibitory effect of n-3 fatty acids on reperfusion-induced arrhythmias.


2014 ◽  
Vol 45 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Hai-Ning Yu ◽  
Jing Zhu ◽  
Wen-sheng Pan ◽  
Sheng-Rong Shen ◽  
Wei-Guang Shan ◽  
...  

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769501 ◽  
Author(s):  
Isha Rani ◽  
Bhoomika Sharma ◽  
Sandeep Kumar ◽  
Satinder Kaur ◽  
Navneet Agnihotri

5-Fluorouracil has been considered as a cornerstone therapy for colorectal cancer; however, it suffers from low therapeutic response rate and severe side effects. Therefore, there is an urgent need to increase the clinical efficacy of 5-fluorouracil. Recently, fish oil rich in n-3 polyunsaturated fatty acids has been reported to chemosensitize tumor cells to anti-cancer drugs. This study is designed to understand the underlying mechanisms of synergistic effect of fish oil and 5-fluorouracil by evaluation of tumor cell–associated markers such as apoptosis and DNA damage. The colon cancer was developed by administration of N,N-dimethylhydrazine dihydrochloride and dextran sulfate sodium salt. Further these animals were treated with 5-fluorouracil, fish oil, or a combination of both. In carcinogen-treated animals, a decrease in DNA damage and apoptotic index was observed. There was also a decrease in the expression of Fas, FasL, caspase 8, and Bax, and an increase in Bcl-2. In contrast, administration of 5-fluorouracil and fish oil as an adjuvant increased both DNA damage and apoptotic index by activation of both extrinsic and intrinsic apoptotic pathways as compared to the other groups. The increased pro-apoptotic effect by synergism of 5-fluorouracil and fish oil may be attributed to the incorporation of n-3 polyunsaturated fatty acids in membrane, which alters membrane fluidity in cancer cells. In conclusion, this study highlights that the induction of apoptotic pathway by fish oil may increase the susceptibility of tumors to chemotherapeutic regimens.


2011 ◽  
Vol 102 (14) ◽  
pp. 7154-7158 ◽  
Author(s):  
Jinyong Yan ◽  
Sanxiong Liu ◽  
Jiang Hu ◽  
Xiaohua Gui ◽  
Guilong Wang ◽  
...  

2008 ◽  
Vol 138 (5) ◽  
pp. 889-896 ◽  
Author(s):  
Eun J. Kim ◽  
Sharon A. Huws ◽  
Michael R. F. Lee ◽  
Jeff D. Wood ◽  
Stefan M. Muetzel ◽  
...  

1992 ◽  
Vol 41 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Setsuko HARA ◽  
Norio OKADA ◽  
Hidehiko HIBINO ◽  
Yoichiro TOTANI

1999 ◽  
Vol 58 (2) ◽  
pp. 377-383 ◽  
Author(s):  
J. R. Sargent ◽  
A. G. J. Tacon

The projected stagnation in the catch from global fisheries and the continuing expansion of aquaculture is considered against the background that fishmeal and fish oil are major feed stocks for farmed salmon and trout, and also for marine fish. The dietary requirement of these farmed fish for high-quality protein, rich in essential amino acids, can be met by sources other than fishmeal. However, the highly-polyunsaturated fatty acids eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) present in high concentrations in fish oil are essential dietary constituents for marine fish and highly-desirable dietary constituents for salmonids. Currently, there is no feasible alternative source to fish oil for these nutrients in fish feeds. Vegetable oils rich in linoleic acid (18:2n-6) can partially substitute for 20:5n-3 and 22:6n-3 in salmonid and marinefish feeds. However, this is nutritionally undesirable for human nutrition because the healthpromoting effects of fish-derived 20:5n-3 and 22:6n-3 reflect a very high intake of 18:2n-6 relative to linolenic acid (18:3n-3) in Western diets. If partial replacement of fish oils in fish feeds with vegetable oils becomes necessary in future, it is argued that 18:3n-3-rich oils, such as linseed oil, are the oils of choice because they are much more acceptable lrom a human nutritional perspective, especially given the innate ability of freshwater fish, including salmonids, to convert dietary 18:3n-3 to 20:5n-3 and 22:6n-3. In the meantime, a more judicious use of increasinglyexpensive fish oil in aquaculture is recommended. High priorities in the future development of aquaculture are considered to be genetic improvement of farmed fish stocks with enhanced abilities to convert C18 to C20 and C22n-3 polyunsaturated fatty acids, enhanced development of primary production of 20:5n-3 and 22:6n-3 by single-cell marine organisms, and continuing development of new species.


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