Effects of dietary fats on fatty acid composition and Δ5 desaturase in normal and diabetic rats

Dang, Alexander; Kemp, Kevin C; Faas, Fred H.; Carter, W. J.

doi:10.1007/bf02535763

Cited by 50 publications

(28 citation statements)

References 26 publications

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“…This decrease in PUFAs involved all of the functionally important fatty acids, including arachidonic acid, EPA and DHA. These observations are in agreement with data reported in diabetic patients [23], and are due probably to reduced 6 -desaturase and 5 -desaturase activities related to diabetes and to increased peroxidation of PUFA by free radicals [24][25][26].…”

Section: Discussionsupporting

confidence: 92%

“…In fact, it has been reported that fish oil induces changes in cholesterol metabolism in rat liver leading to increases in biliary excretion of cholesterol [37]. Indeed, the dietary EPAX intake by mothers and their macrosomic pups induced a large increase in n − 3 PUFA levels, followed by a large decrease in arachidonic acid, in agreement with previous results [11,24]. DHA has been shown to inhibit the conversion of C 18:2n−6 into C 20:4n−6 by decreasing 6 -desaturase activity [38], which may explain the increased C 18:2n−6 and decreased C 20:4n−6 in serum and liver of the diabetic rats fed the EPAX diet.…”

Section: Discussionsupporting

confidence: 82%

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Modulation of lipid metabolism by n−3 polyunsaturated fatty acids in gestational diabetic rats and their macrosomic offspring

et al. 2005

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The time course of changes in lipid metabolism by dietary n-3 PUFAs (polyunsaturated fatty acids) in streptozotocin-induced diabetic rats during pregnancy (days 12 and 21) and their macrosomic offspring at birth (day 0) and through adulthood (days 60 and 90) was studied with respect to adipose tissue, liver and serum lipid concentrations, and fatty acid composition. Glucose and insulin levels were also assessed in order to characterize the diabetic state of macrosomic offspring. Pregnant diabetic and control rats were fed either an Isio-4 or EPAX diet (enriched with n-3 PUFA). The same diets were also consumed by pups at weaning. Compared with control rats, during pregnancy diabetic rats had a significant elevation in liver and serum triacylglycerol (triglyceride) and cholesterol concentrations. At birth, macrosomic pups had higher serum insulin and glucose levels than control pups. The macrosomic rats maintained accelerated postnatal growth combined with high adipose tissue weight and lipid content through the first 12 weeks of age. The macrosomic pups from diabetic rats fed the Isio-4 diet also showed a significant enhancement in liver and serum triacylglycerol and cholesterol levels at birth and during adulthood. Feeding the EPAX diet to diabetic mothers as well as their macrosomic pups increased serum and liver levels of EPA (eicospentaenoic acid) and DHA (docosahexaenoic acid) with a reduction in arachidonic acid. The EPAX diet induced a significant decrease in liver and serum triacylglycerol and cholesterol concentrations in mothers during pregnancy and in their macrosomic pups during adulthood. Since the EPAX diet improves lipid anomalies considerably in diabetic mothers and their macrosomic offspring, it may prevent long-term metabolic abnormalities associated with macrosomia.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 82%

Modulation of lipid metabolism by n−3 polyunsaturated fatty acids in gestational diabetic rats and their macrosomic offspring

et al. 2005

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“…This shows that the A 6 desaturase activity is relatively unaffected by PUFA deficiency, while that of `5 5 desaturase is reduced. Reduction in ,5 5 desaturase activity has also been proposed in rats fed PUFA deficient diets (Dang et al 1989). Feeding the commercial diet to fish virtually diminished elongation and desaturation in both polar and neutral lipid classes, showing the impof tance of diet on lipogenic processes.…”

Section: Resultsmentioning

confidence: 97%

Lipids of arctic charr,Salvelinus alpinus (L.) II. Influence of dietary fatty acids on the elongation and desaturation of linoleic and linolenic acid

Olsen

Ringø

1992

Fish Physiol Biochem

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Arctic charr,Salvelinus alpinus L. were fed five test diets containing 0% or 1% of different polyunsaturated fatty acids (PUFA) for 93 days. The fish were injected intraperitoneally with (1-(14)C)-18:2(n-6) or (1-(14)C)-18:3(n-3), and the bioconversion to longer chain PUFA studied. The conversion rate in neutral lipids was slow, with most label found as the fatty acid injected, while extensive modification took place prior to or during incorporation into polar lipids. Linolenic acid was preferred over linoleic acid as substrate for elongation and desaturation regardless of diet. In polar lipids, the predominant products of (1-(14)C)-18:2(n-6) metabolism were generally 20:3(n-6) and 20:4(n-6), while 18:4(n-3), 20:5(n-3) and 22:6(n-3) were the major products of (1-(14)C)-18:3(n-3) metabolism. The lack of radioactivity in 22:5(n-6) suggests that Δ 4 desaturation is specific for (n-3) PUFA. Feeding the PUFA deficient diet reduced the Δ 5 desaturation compared to fish maintained on PUFA supplemented diets. The Δ 6 desaturation was only reduced in fish fed C18 PUFA and injected with (1-(14)C)-18:3(n-3). Longer chain C20 and C22 PUFA, particularly those of the (n-3) family, exerted some inhibition on the elongation and desaturation of injected fatty acids compared to those fed C18 PUFA. The incorporation of radiolabelled fatty acids into polar lipids of fish fed a commercial diet was very low, and the desaturation neglectible in both polar and neutral lipids, showing that Arctic charr under culture conditions do not convert short chain PUFA to longer chain metabolites.

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“…Some of these changes, the decreases in palmitoleate and arachidonate and the increases in linoleate and eicosatrienoate are probably due to diminished A 9 , A 6 , and A 5 desaturase activities in the diabetic liver (4,5). For nomenclature of fatty acids referred to in this article, please see Table 1.…”

mentioning

confidence: 98%

Decreased Incorporation of Long-Chain Fatty Acids into Erythrocyte Phospholipids of STZ-D Rats

Dang

Faas²,

Jethmalani³

et al. 1991

Diabetes

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We studied the mechanisms for the altered fatty acid composition in erythrocytes (RBCs) derived from streptozocin-induced diabetic (STZ-D) rats. After 3-wk duration of diabetes, blood glucose, plasma triglyceride, and plasma free-fatty acid levels were all significantly increased. In the diabetic platelet-poor plasma (PPP), the most significant increases in free fatty acids were stearate, linoleate, eicosatrienoate (n-6), and docosahexaenoate (n-3). Fatty acid composition of RBC phospholipids was also altered, with significant decreases in arachidonate, docosatetraenoate (n-6), and docosapentaenoate (n-6) and increases in linoleate and docosahexaenoate. Insulin treatment of the diabetic rats resulted in normalization of docosapentaenoate, arachidonate, and linoleate levels in RBC phospholipids but not of docosahexaenoate or docosatetraenoate levels. The incorporation of [5,6,8,9,11,12,14,15-3H]arachidonate into diabetic RBC phospholipids was significantly decreased compared with the corresponding control RBC, regardless of the incubation medium used, which was the PPP derived either from the control or diabetic rats. Therefore, the decreased incorporation of [5,6,8,9,11,12,14,15-3H]arachidonate into diabetic RBC phospholipids was independent of the altered lipid composition of the PPP incubation media. Furthermore, the decreased incorporation was not specific for arachidonate, because the incorporation of other long-chain fatty acids such as [9,10-3H]oleate, [1-14C]palmitate, [2-14C]eicosatrienoate (n-6), and [1-14C]linoleate into RBC phospholipids was also comparably decreased. More important, the decreased fatty acid incorporations were reversed by insulin treatment of the diabetic rat.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effects of dietary fats on fatty acid composition and Δ5 desaturase in normal and diabetic rats

Cited by 50 publications

References 26 publications

Modulation of lipid metabolism by n−3 polyunsaturated fatty acids in gestational diabetic rats and their macrosomic offspring

Modulation of lipid metabolism by n−3 polyunsaturated fatty acids in gestational diabetic rats and their macrosomic offspring

Lipids of arctic charr,Salvelinus alpinus (L.) II. Influence of dietary fatty acids on the elongation and desaturation of linoleic and linolenic acid

Decreased Incorporation of Long-Chain Fatty Acids into Erythrocyte Phospholipids of STZ-D Rats

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