Retroconversion and δ4 desaturation of docosatetraenoate (22:4(n−6)) and docosapentaenoate (22:5(n−3)) by human cells in culture

Rosenthal, Miriam D.; Garcia, M.C.; Jones, M.; Sprecher, Howard

doi:10.1016/0005-2760(91)90121-w

Cited by 72 publications

(28 citation statements)

References 44 publications

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“…Most n-6 metabolites (18:3n-6, 20:2n-6 and 20:3n-6) did not accumulate and the main elongation and desaturation product of the n-6 series was 20:4n-6 which is essential for growth, cell signalling, and an eicosanoid precursor (Innis, 2003). Moreover, 20:4n-6 tended to resist further conversion into 22:4n-6 but this may have been also due to retroconversion of 22:4n-6 back to 20:4n-6 as observed in human cells (Rosenthal et al, 1991). Overall, the conversion of 18:2n-6 and accumulation of 20:4n-6 appeared to take place at a similar rate in all genotypes although some significant differences were found for n-6 fatty acid intermediates with lower concentrations (18:3n-6, 20:2n-6, 20:3n-6).…”

Section: Resultsmentioning

confidence: 98%

N-6 and n-3 fatty acids in different beef adipose tissues depending on the presence or absence of the gene responsible for double-muscling

Aldai¹,

Dugan²,

Nájera³

et al. 2008

CZECH J ANIM SCI

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Levels of n-6 and n-3 PUFAs, including those with 20 and 22 carbon-chains, in concentrate-fed Asturiana de los Valles (AV) yearling bulls with and without the double muscling gene (mh/mh = 24, mh/+ = 26, +/+ = 25) were measured to examine if this gene influences the pattern of PUFA deposition in different adipose tissues. Fatty acid compositions of muscle tissue (longissimus thoracis) and intermuscular and subcutaneous adipose tissues were determined by gas chromatography. The composition of intramuscular fat was unique compared to the other two adipose tissues which were similar in composition. In general, n-6 and n-3 fatty acid elongation and desaturation products were affected by AV genotype and this effect was most evident in n-3 PUFAs of the intramuscular fat of mh/mh (n-6/n-3 = 11.8 and 18:2n-6/18:3n-3 = 25.3) compared to mh/+ and +/+ animals (mean values of n-6/n-3 = 9.86 and 18:2n-6/18:3n-3 = 15.5). PUFA elongation and desaturation end products did not accumulate to any great extent in intermuscular and subcutaneous adipose tissues. Beef from mh/mh cattle showed greater deposition rates of n-3 elongation and desaturation products but their absolute content of total n-3 fatty acids was lower (21 mg/100 g meat) in comparison with mh/+ and +/+ cattle (mean value of 25 mg/100 g meat).

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Section: Resultsmentioning

confidence: 98%

N-6 and n-3 fatty acids in different beef adipose tissues depending on the presence or absence of the gene responsible for double-muscling

Aldai¹,

Dugan²,

Nájera³

et al. 2008

CZECH J ANIM SCI

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“…Retroconversion of DHA to 22:5n-3 and EPA has been observed previously in various animal tissues [30][31][32] and retroconversion of DHA to 22:5n-3 and EPA, and 22:5n-3 to EPA has been reported in various cells in culture. 22,[33][34][35] In contrast, in rat U III (uterine stromal) cells, which show higher levels of DHA production from 18:3n-3 than most other cell lines, there was no significant retroconversion of DHA, added at 5 µM. 36 To our knowledge the effects of EFA deficiency on retroconversion processes in cell cultures has not been reported previously, but retroconversion of DHA to EPA and 22:5n-3 was reported to be increased in hepatocytes prepared from salmon fed an EFA deficient diet in comparison with hepatocytes from salmon fed an n-3PUFA supplemented diet.…”

mentioning

confidence: 99%

Effects of essential fatty acid deficiency and supplementation with docosahexaenoic acid (DHA; 22:6n-3) on cellular fatty acid compositions and fatty acyl desaturation in a cell culture model

Tocher

Dick

2001

Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA)

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“…The DHA to EPA retroconversion is known to occur in a variety of animal tissues, while retroconversion of AA is not as well documented (Rosenthal et al, 1991). (Figure 3).…”

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confidence: 99%

n-3 and n-6 fatty acid processing and growth effects in neoplastic and non-cancerous human mammary epithelial cell lines

Grammatikos¹,

Subbaiah²,

Victor³

et al. 1994

Br J Cancer

144

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The type rather than the amount of dietary fat may be more important in breast carcinogenesis. While animal studies support this view, little is known about the effects of essential fatty acids (EFAs) at the cellular level. The MCF-7 breast cancer and the MCF-10A non-cancerous human mammary epithelial cell lines are compared in terms of growth response to EFAs and ability to incorporate and process the EFAs. Eicosapentaenoic (EPA, n-3) and docosahexaenoic (DHA, n-3) acids, presented bound to albumin, inhibited the growth of MCF-7 cells by as much as 50% in a dose-dependent manner (6-30 microM) in medium containing 0.5% serum. alpha-Linolenic (LNA, n-3) and arachidonic (AA, n-6) acids inhibited growth less extensively, while linoleic acid (LA, n-6) had no effect. In contrast, MCF-10A cells were not inhibited by any of the EFAs at levels below 24 microM. The differential effects of AA, EPA and DHA on MCF-7 and MCF-10A cells support a protective role of highly unsaturated essential fatty acids against breast cancer. The EFAs were primarily incorporated into phosphoglycerides. MCF-7 cells showed chain elongations and possibly delta 8 desaturation, but no AA was formed from LA, nor EPA or DHA from LNA. In contrast, MCF-10A cells desaturated and elongated the exogenous EFAs via all the known pathways. These findings suggest defects in the desaturating enzymes of MCF-7 cells. LNA, DHA and AA presented to MCF-7 cells in phospholipid liposomes inhibited growth as extensively as albumin-bound free acids, but were less extensively incorporated, suggesting different mechanisms of inhibition for the two methods.

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Retroconversion and δ4 desaturation of docosatetraenoate (22:4(n−6)) and docosapentaenoate (22:5(n−3)) by human cells in culture

Cited by 72 publications

References 44 publications

N-6 and n-3 fatty acids in different beef adipose tissues depending on the presence or absence of the gene responsible for double-muscling

N-6 and n-3 fatty acids in different beef adipose tissues depending on the presence or absence of the gene responsible for double-muscling

Effects of essential fatty acid deficiency and supplementation with docosahexaenoic acid (DHA; 22:6n-3) on cellular fatty acid compositions and fatty acyl desaturation in a cell culture model

n-3 and n-6 fatty acid processing and growth effects in neoplastic and non-cancerous human mammary epithelial cell lines

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