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Biomedical subjects

E Turchetto

Publications and source records attributed to E Turchetto.

At least 37 records · Page 2Linked to original sources
PubMed1990

Influence of docosahexaenoic acid on phosphatidylinositol metabolism in cultured cardiomyocytes.

Polyunsaturated fatty acids are involved at several steps in the turnover of phosphatidylinositol mediated by alpha 1-adrenoceptors. We have cultured neonatal rat cardiomyocytes in a medium containing docosahexaenoic acid (C22:6n3) and have investigated the effects produced by the change in the fatty acid composition of phosphatidylinositol on alpha 1-adrenoceptor-mediated phosphatidylinositol metabolism. The experimental cells, in which phosphatidylinositol was significantly enriched in docosahexaenoic acid and depleted in arachidonic acid, showed a reduced ability to incorporate labeled inositol into phospholipids in comparison with control cells, both in basal conditions and after stimulation by phenylephrine. This decreased incorporation led to a reduced availability of inositol phospholipids, substrates of phospholipase C, and to a reduced production of inositol phosphates under basal conditions.

Animals↗
PubMed1989

[Effects of polyunsaturated phosphatidylcholine in alcoholic liver diseases].

The aim of this study is to assess "in vitro" the influence of polyunsaturated phosphatidylcholine on the erythrocyte membrane fluidity in alcoholics (greater than 180 g/die) and control subjects (less than 50 g/die), investigated by the evaluation of fluorescent polarization of DPH. In both groups a significant increase of membrane microviscosity was observed after incubation with 0.04 microM and 0.08 microM of PC compared to baseline values.

Adult↗
PubMed1989

Age-related changes in linoleate and alpha-linolenate desaturation by rat liver microsomes.

The first and rate limiting step in the conversion of linoleic and alpha-linolenic acid is catalyzed by the delta - 6 - desaturase (D6D) enzyme. Rat liver microsomal D6D activity decreases on linolenic acid at a rate proportional to the animal age; on alpha-linolenic acid the decrease in D6D activity begins only later than on linoleic acid. The fatty acid composition of liver microsomes determined by gas chromatographic analysis confirms the impairment of the enzymatic activity directly measured. Our data indicate a correlation between aging and D6D activity impairment. The loss of D6D activity may be a key factor in aging through altering the eicosanoid balance.

Aging↗
PubMed1989

Dietary-induced changes in lipid and fatty acid composition can modify chronaxie values in the rat sciatic nerve.

The present investigation aimed at clarifying the possible correlations among dietary lipids, peripheral fatty acid composition of nerve lipids and an index of the nervous tissue excitability, the chronaxie. The experiments were performed on female albino rats fed diets containing olive oil (OO) and fish oil (FO) along two generations. Total lipids fatty acid composition of the sciatic nerves from the two groups differed in the proportions of 18:1(n-9), 20:1(n-9), 22-1, 20:5(n-3) and 22:6(n-3). Also the lipid class composition showed significant differences among FO and OO specimens (free cholesterol more concentrated in the OO lipids; triacylglycerols more concentrated in the FO ones). The sciatic nerve isolated from FO rats showed a significant decrease in the chronaxie values if compared to the OO specimens. These results could follow from dietary-induced changes in the perineural permeability and/or possible modifications in the cable properties of the peripheral nerve fibers related to the myelin sheath composition.

Animals↗
PubMed1988

Effect of n-6 and n-3 dietary fatty acids on phospholipid composition of plasma, platelets and aorta in the rat.

Female Wistar rats were fed with diets containing as dietary lipids 10% of hydrogenated coconut oil, grape-seed oil, olive oil, linseed oil and fish oil, respectively, for a period of 60 days. At the end of dietary treatment plasma, platelets and aorta phospholipids were extracted and fatty acid spectra determined. Plasma and platelet phospholipids showed the largest diet dependent changes. Anyway in aorta samples too, phospholipids showed marked increase in oleic (olive oil group) linoleic (grape-seed oil group) and alpha linoleic (linseed oil group) acids percentage. Conversely decreased amounts of arachidonic acid were detected in rats fed with diets containing linseed and fish oils. In these samples eicosapentenoic acid partly replaced arachidonic one.

Animals↗
PubMed1988

Aging influence on delta-6-desaturase activity and fatty acid composition of rat liver microsomes.

The activity of delta-6-desaturase (D6D) in liver microsomes and fatty acid composition of microsomal lipids of rats of different ages were studied. The D6D activity was similar in suckling rats and in weaning rats. However, the enzyme showed a significantly decreased activity in oldest animals, and a linear correlation was found between the D6D activity and the animal age. The fatty acid composition data on total lipids of liver microsomes were consistent with the age-dependent changes in fatty acid desaturase activity. The major changes occurred in the linoleate and arachidonate fractions; the 20:4/18:2 ratio in liver microsomes decreased together with D6D activity during aging. The loss of D6D activity may be a key factor in aging through altering lipid membrane composition.

Aging↗
PubMed1984

Effect of C 18:3 (n-3) dietary supplementation on the fatty acid composition of the rat brain.

Weanling rats have been fed different diets containing hydrogenated coconut oil or a mixture of grapestone + linseed oil as dietary fats. Groups of 12 animals have been sacrificed at weanling or after 60 or 120 days of this dietary treatment. Body and brain weight, brain total lipids, phospholipids, cholesterol, cerebroside, fatty acid content and fatty acid composition have been evaluated. The diet rich in alphalinolenic acid (C 18:3 n-3) induced a significant increase of the n-3 polyunsaturated fatty acids (C 22:5 and C 22:6, n-3) in the brain, with respect to the other experimental conditions.

Animals↗
PubMed1984

Fatty acid composition of single brain structures following different alpha linolenate dietary supplementations.

Weanling female rats randomly divided into three groups were fed a basal alipidic diet added with 10% (w/w) corn oil, soybean oil or linseed oil. After thirty and ninety days of dietary treatment the rats were killed and the fatty acid composition of brain, optic nerve and visual cortex was determined. The results demonstrate a different sensitivity to the diet of the different structures examined and, for the linseed oil treated rats, a strong decrease in the proportions of the total (n-6 + n-3) polyunsaturated fatty acids in all the structures examined.

Animals↗
PubMed1982

[Protection of essential fatty acids by vitamin E].

The protective role of vitamin E against free-radical-mediated oxidations is discussed. In spite of the presence of vitamin E in cell membranes, as structural complex with polyunsaturated fatty acids (PUFA) of phospholipids, the question arises whether high PUFA containing diets, producing high deposition of PUFA in the tissues, can nevertheless lead to peroxidations in the body. It has been suggested that large amounts of dietary PUFA increase the requirement for vitamin E and deplete its tissue stores, particularly when PUFA are discontinued in the diet, also because of their longer half-life time than tocopherols. However, in physiological conditions, linoleic acid up to 10% of caloric intake seems to have no effects on vitamin E requirement. In contrast, in essential fatty acid (EFA) deficient animals, also the addition of small amounts of dietary EFA, by resulting in a proportional increase in PUFA content of membrane structural lipids, is associated with an increased need for vitamin E. This becomes particularly important in the case of dietary fish oils or other poorly protected fats.

Animals↗
PubMed1980

Different lipid effects on hematic cholesterol.

Literature fully reports that a polyunsaturated fatty acids suitability reduces cholesterolaemia levels. Many authors regard as very useful for the same purpose phospholipid intakes; certainly this event requires LCAT availability too. In this work we have tried to check EFA, phospholipid and different mixtures of both effects on rat's cholesterolaemia. The research was divided in two tests (3 days long the first, 60 days long the second); the best results for mentioned steroid control, were not proportional as one could suppose, but the effect was positive only for a particular range of mixtures. The achieved results may be explained with an extremely favourable substrata availability, both for quality and amount.

Animals↗
PubMed1980

Biometabolic effects of different nutrients on embryonal cultures.

It has been valued the effects of different nutrients (glucose, phospholipids and ethanol) on the growth and morphology of chicken embryo cells, cultured in vitro by "pendent drop". Considering that the basal nourishing substratum used in these studies is the best medium that may be supplied to the cultures for the growth of this kind of tissues, the entity of damage induced by different nutrients has been shown. It may be said that the less negative effect is induced by 2.5% ethanol and by the association: "glucose + 2.5% ethanol", that the damage induced by only glucose seems to improve in presence of 2.5% ethanol, that in presence of phospholipids the cells appear all full of big lipid drops (especially in the condition: "phospholipid + ethanol") and that 5% ethanol deeply appears to impair and alter the cultures, as it was been observed in our previous experiences.

Animals↗