• Nutritional Sciences
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• 제5권4호
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• pp.184-189
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• 2002

The effects of dietary Int levels on lipid metabolism under fixed P/S (1.3) and n-6/n-3 (5.1) fatty acid ratios were examined in rats using palm oil, soybean oil and perilla oil. These ratios correspond to the recommended composition of dietary fat for humans. The range of dietary fat levels was 5-20% by weight (11.8-39.3% of total energy). The levels of dietary fat did not influence the concentrations of serum and liver cholesterol, whereas the level of triglycerides was gradually elevated with increasing levels of dietary fat, especially in the liver. The fatty acid composition of tissue phosphatidylcholine seemed to vary with the different levels of fat. The ratio of linoleic acid to arachidonic acid was increased more significantly in the heart than in the liver. In adipose tissue total lipids, the percentages of saturated and monounsaturated fatty acids decreased, whereas the percentage of polyunsaturated fatty acid increased, with increasing dietary Int levels. In addition, though the level of aortic prostacyclin was not uniformly affected by increasing dietary fat levels, thromboxane A2 production by platelets tended to increase with higher levels of dietary fat, suggesting an increased risk of thrombosis in this situation. Thus, even though dietary fat may have desirable compositions of fatty acids, these excessive consumption can produce unfavorable metabolic responses.

• Journal of Applied Biological Chemistry
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• 제42권2호
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• pp.75-80
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• 1999

The effects of dietary n-3 fatty acids, ${\alpha}$-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6), on brain phospholipid content and fatty acid composition were compared in rats fed with a diet containing constant ratios of saturated fatty acid/monounsaturated fatty acid/polyunsaturated fatty acid (PUFA) and n-3/n-6. The dietary fat in each diet was added at the level of 10%. In each diet, n-3 PUFA comprised two-thirds of the PUFA and the remaining one-third was linoleic acid (18:2). Dietary fat containing linoleic acid as the sole source of PUFA was also given to the control group. The content of brain phospholipid in the three n-3 PUFA groups was significantly lower than that of the linoleic acid group. This reduction was greater in the EPA and DHA groups than in the ${\alpha}$-linolenic acid group. The decrease in phospholipid content in rats fed n-3 fatty acid-rich diets was largely due to the decrease in the phosphatidylethanolamine fraction. Each dietary n-3 PUFA was found to affect the fatty acid composition of brain phospholipids; the most pronounced alteration was observed in phosphatidylethanolamine fraction. Furthermore, the proportion of DHA in the phosphatidylethanolamine fraction tended to be higher in the DHA group than in other PUFA groups. In conclusion, dietary ${\alpha}$-linolenic acid, EPA and DHA can influence the phospholipid content, phospholipid subclass, and fatty acid composition in rat brain.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1413-1421
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• 2013

The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

• Nutritional Sciences
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• 제9권1호
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• pp.9-13
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• 2006

The differential effects of various fatty acids such as n-3 and n-6 types or degrees of unsaturation on the CYP2E1 induction and the production of lipid peroxidation (LPO) were investigated. The CYP2E1-transduced human hepatoma HepG2 cells (E47) were cultured in RPMI 1640 media containing different concentrations of various fatty acids up to 48 h incubation compared to 04 cells and CYP2E1-null cells. Treated fatty acids were linoleic acid (LA:n-6, C18:2), arachidonic acid (AA:n-6, C20:4) and docosahexaenoic acid (DHA:n-3, C22:6). The cell survival rate was decreased corresponding to the degree of unsaturation (LA>AA $\cong$DHA) and to LPO production in E47 and 04 cells. The four or five unsaturation degree of fatty acids, AA and DHA, caused time- and dose-dependent cell death in E47 cells but not as much as in C34 (without CYP2E1), suggesting an important role of CYP2E1 in the DHA mediated damage. In the levels of lipid peroxides (LPO), AA also elevated LPO by 3- and 5- fold compared to DHA or LA treated E47 cells. However, AA did not increase LPO until 48 h incubation in C34 cells. In conclusion, the polyunsaturated fatty acids induced CYP2E1 induction might be changed by the elevated levels of lipid peroxide (LPO) and oxidative stress through the connection of CYP2E1 and degrees of unsaturated fatty acids.

• 한국응용과학기술학회지
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• 제13권3호
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• pp.15-24
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• 1996

Essentiality was proposed in the field of lipid by Burr and Burr in 1929. When rats were raised on the fat-free diet, their growth retarded and their skin and tails showed the characteristic deficient symptoms, which were relieved by the addition of ${\omega}6(n-6)$ polyunsaturated fatty acids as linoleic(LA) and arachidonic(AA) acids to the basal diet. LA is dehydrogenated to ${\gamma}-linolenic$ acid(GLNA) by ${\Delta}6$ desaturase, then GLNA is 2 carbon chain elongated by elongase to $dihomo-{\gamma}-linolenic$ acid(DGLNA), which is desaturated by ${\Delta}5$ desaturase to AA. These acids are called LA family or ${\omega}6(n-6)$ polyunsaturated fatty acids(PUFA). ${\alpha}-Linolenic$ acid(ALNA) is converted through the series of desaturation and elongation steps to docosahexaenic acid(DHA) via eicosapentaenoic acid(EPA). These acids belong to ALNA family or ${\omega}3(n-3)$PUFA. Human who consume large amounts of EPA and DHA, which are present in fatty fish and fish oils, have increased levels of these two fatty acids in their plasma and tissue lipids at the expense of LA and AA. Alternately, vegetarians, whose intake of LA in high, have more elevated levels of LA and AA and lower levels of EPA and DHA in plasma lipids and in cell membranes than omnivores. AA and EPA are metabolized to substances called eicosanoids. Those derived form AA are known as prostanocids(prostaglandins and prostacyclins) of the 2-types and leukotrienes of the 4-series, whereas those derived from EPA are known as prostanoids of the 3-types and leukotrienes of the 5-series. DGLNA is a precursor of the 1-types of prostaglandins. The metabolites of AA and EPA have competitive functions. Ingestion of EPA from fish or fish oil replaces AA from membrane phospholipids in practically all cells. So this leads to a more physiological state characterized by the production of proatanoids and leukotrienes that have antithrombic, antichemotactic, antivasoconstrictive and antiinflammatory properties. It is evident that ${\omega}3$ fatty acids can affect a number of chronic diseases through eicosanoids alone.

• 한국축산식품학회지
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• 제26권4호
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• pp.517-524
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• 2006

계란 품질, 난황 콜레스테롤 함량 및 지방산 조성의 변화에 관한 산란계 사료 내 서로 다른지방의 첨가효과를 조사하였다. 36주령의 Hyline brown 산란계 총 200수(4처리구${\times}$50수/반복)를 공시하여 우지, 옥수수유, 아마인유 및 어유를 각각 5.0% 함유하는 실험사료를 10주간 급여하였다. Haugh unit, 파란 강도, 난각 두께 및 난황색에 대한 처리구 간 유의적 차이는 나타나지 않았다. 첨가지방은 계란 콜레스테롤 함량과 고도 불포화지방산 조성을 현저하게 변화시켰다. 난황의 n-6지방산 함량은 옥수수유 첨가구가 31.61%로써 가장 높았고 우지, 아마인유 및 어유 첨가구순으로 낮았으며, n-3 지방산 함량은 아마인유와 어유 첨가구가 각각 9.74%, 5.16%로써 유의적 증가 경향을 나타냈다(p<0.05). 난황지방 산 조성의 n-3지방산 증가는 계란 콜레스테롤 함량 감소를 초래하였다. 난황 콜레스테롤(mg/g yolk) 및 계란 콜레스테롤(mg/60g egg) 범위는 각각 $15.98{\sim}18.37mg$ 및 $227{\sim}261mg$으로써 우지 첨가구가 가장 높았고 어유, 아마인유 및 옥수수유 첨가구 순으로 낮아지는 경향을 보였다(p<0.05). 난황 콜레스테롤의 감소율은 우지 첨가구와 비교하였을 때 어유 13.01%, 아마인유 11.49% 및 옥수수유 6.91%로써 유의적인 차이를 나타냈다(p<0.05). 이상의 결과는 산란계 사료 내 첨가되는 지방급원을 조절해 줌으로써 계란 콜레스테롤을 낮출 수 있으며 n-6와 n-3 지방산을 난황으로 축적하는 것이 가능함을 시사해준다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.622-637
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• 2017

Fatty acids such as n-3 and n-6 polyunsaturated fatty acids (PUFA) are critical nutrients, used to improve male reproductive performance through modification of fatty acid profile and maintenance of sperm membrane integrity, especially under cold shock or cryopreservation condition. Also, PUFA provide the precursors for prostaglandin synthesis and can modulate the expression patterns of many key enzymes involved in both prostaglandin and steroid metabolism. Many studies carried out on diets supplemented with PUFA have demonstrated their capability to sustain sperm motility, viability and fertility during chilling and freezing as well as improving testis development and spermatogenesis in a variety of livestock species. In addition to the type and quantity of dietary fatty acids, ways of addition of PUFA to diet or semen extender is very crucial as it has different effects on semen quality in male ruminants. Limitation of PUFA added to ruminant ration is due to biohydrogenation by rumen microorganisms, which causes conversion of unsaturated fatty acids to saturated fatty acids, leading to loss of PUFA quantity. Thus, many strategies for protecting PUFA from biohydrogenation in rumen have been developed over the years. This paper reviews four aspects of PUFA in light of previous research including rumen metabolism, biological roles, influence on reproduction, and strategies to use in male ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.565-569
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• 2003

The objective of this experiment was to determine the effects of different levels of refined cod liver oil (RCLO) on laying performance, n-3 polyunsaturated fatty acids composition (n-3 PUFAs) and the organoleptic evaluation of duck egg yolks. A total of 180 30 wk old laying Tsaiya ducks, at the beginning of peak production, were allotted into 6 treatments with 3 replicates each. Ducks were fed one of the 6 experimental diets, supplemented with 2% tallow (control) and graded levels of RCLO at 2, 3, 4, 5, and 6% to a corn-soybean diets, respectively, for 6 wks. All of the experimental diets were formulated to be both isocaloric and isonitrogenous. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the RCLO supplementation levels did not affect (p>0.05) egg production, egg mass, feed intake, feed efficiency or body weight change. Egg weight was the lightest when the ducks received the 6% RCLO diet. The eicosapentaenoic acid, docosahexaenoic acid, and total n-3 PUFAs contents in the yolks increased with increasing RCLO supplementation. The taste and general acceptability of the hard-boiled eggs were not significantly different among the treatments. However, a fishy flavor was much higher when ducks were fed diets supplemented with 5% and 6% RCLO diets.

• 한국식품영양과학회지
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• 제31권2호
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• pp.184-188
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• 2002

시료 달걀의 난황 속에는 올레산과 팔미트산이 가장 많이 함유되어 있었고, 저장 1, 2주에 그 함량이 최고점으로 도달 하였으며, 3주 때는 감소하였다. 일반란의 경우 저장기간이 길어질수록 팔미트산과 올레산은 증가 후 다시 감소하였고, 리놀레산은 증가하였다. 인삼란의 경우 팔미트산과 스테아르산이 감소 경향을 보였다. DHA란의 팔미트산과 올레산의 변화는 없었으나, 리놀레산이 증가하였다 감골란은 올레산이 급격히 감소의 경향을 보이는 반면, 팔미트산은 증가 후 감소의 경향을 반복하였다. 저장기간이 길어짐에 따라 포화 지방산의 함량은 감소하고 불포화지방산의 함량은 증가하는 경향을 보였다. 구입 당시 모든 달걀에 나타나지 않았던 DHA가 저장기간 동안에 극미량 검출되었다. 한편, n-6/n-3 비율은 일반란이 저장 1~3주, 감골란은 구입 당시, DHA란은 저장 0~3주의 저장기간 동안 섭취 권장 범위에 해당되었다. 저장기간 동안 다중불포화지방산, 단일불포화지방산과 포화 지방산의 비 (P/M/S)가 DHA란은 변화가 없었고, 인삼란은 점차 증가하는 경향을 보였다. P/M/S비는 3주 저장한 일반란, 2주 저장한 인삼란과 0~3주 저장기간의 DHA란에서 적정권장 수준을 나타내었다.

• 한국식품영양과학회지
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• 제23권4호
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• pp.548-554
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• 1994

In order to observe the effects of the feeds mixed with the lard and two vegetable seed oils on the fatty acid compositions of serum lipkid and lipoprotein, the oils mixed with 2.5% lard and various levels of perilla oil and evening promrose oil were administered to the male rats of the Sprague-DAwley for 4 weeks. In the fatty acid compositions of serum lipid and serum lipoprotein fractions, as the content so f mixed perilla oil decreased and the contents of mixed evening primrose oil increased, n -3 PUFa (polyunsaturated fatty acid) contents and ratio of EPA/AA (eicisapentaenoiidacid/arachidonic acid) tended to decrease, but n-6 PUFA contents and ratio of AA/PUFA tended to increase. Fatty acid compositions of serum lipid and serum lipoprotein fractions were influenced from the fatty acid composition of the test lipids.