Biomedical subjects

K R McAdoo

Publications and source records attributed to K R McAdoo.

8 recordsLinked to original sources

PubMed1988

Effects of calcium deprivation on n-6 fatty acid metabolism in growing rats.

Two separate experiments examining the effects of calcium deficiency on plasma and liver fatty acids in rats were conducted. In Experiment I, weanling male Sprague-Dawley rats were fed a calcium-deficient diet with or without the supplementation of 5 or 20 g/kg calcium for 22 days. There were no significant differences in plasma and liver fatty acid distribution between the two calcium-supplemented groups. However, calcium deficiency significantly elevated the levels of 18:3n-6 in plasma and liver cholesteryl esters and liver phospholipids, while it reduced the levels of 20:3n-6 in plasma cholesteryl esters. In Experiment II, weanling rats were fed a calcium-deficient diet supplemented with 5 g/kg calcium for 22 days. After overnight fast, animals were given by intragastric feeding a dose of 4 g/kg body wt gamma-linolenic acid concentrate (containing 92% 18:3n-6 ethyl ester), and were killed 22 hr later. The levels of 18:3n-6 were significantly higher, whereas the levels of 20:3n-6 were either not changed or lower than those in calcium-supplemented group. In both experiments, the ratios of (20:3n-6 + 20:4n-6)/18:3n-6 in plasma and liver lipids were significantly reduced in calcium-deficient rats. These results suggest that calcium may play an important and specific role in the process of elongation of 18:3n-6 to 20:3n-6.

Aging↗

PubMed1988

Copper intake affects rat heart performance during ischemia-reperfusion: possible relation to altered lipid and fatty acid metabolism.

Hearts from rats fed low copper (1.3 mg copper/kg diet) or a copper-supplemented diet (243 mg copper/kg diet) were perfused for 90 min according to the Langendorff method. The perfusion protocol included 30 min normoxia, 30 min ischemia and 30 min reperfusion. After 90 min perfusion, hearts from the low copper group had gained more weight, had lower coronary perfusion pressure, developed less force of contraction and secreted less 6-keto PGF1 alpha into the perfusate than hearts from the copper-supplemented group. After perfusion, the major lipid change in the hearts from both groups was a 85-90% decrease in total triacylglycerol. In both groups, stearic acid and arachidonic acid (mg%) were increased in the triacylglycerol fraction after heart perfusion. The quantitative (mg/g) decrease in the triacylglycerol content of stearic acid and arachidonic acid was significantly less in the copper-supplemented group. After perfusion, dihomo-gamma-linolenic acid (mg/g) was lower in heart phospholipids from the low copper group. Dihomo-gamma-linolenic/arachidonic acid (microgram/mg) was significantly decreased after perfusion only in the hearts from the low copper group. Lipid and fatty acid changes in the hearts of the rats fed low dietary copper may contribute to abnormal heart function in this group.

Animals↗

PubMed1987

Iron intake influences essential fatty acid and lipid composition of rat plasma and erythrocytes.

In view of the clinical importance of iron deficiency as well as the known role of iron in stearic acid desaturation, the effects of higher or lower iron intake on fatty acid composition of blood and liver in the rat were studied. Male Sprague-Dawley rats were fed purified diets that contained iron at 12, 27 or 237 mg/kg. After 12 wk the lipid and fatty acid composition of plasma, erythrocytes and liver was analyzed. Linoleic acid in plasma phospholipids and triacylglycerols was higher, but arachidonic acid was lower in the group fed 12 mg/kg iron than in the groups fed 27 or 237 mg/kg iron. Liver fatty acid and lipid composition was not different between groups. In the group fed 237 mg/kg iron, plasma cholesterol and triacylglycerols were 150%, erythrocyte cholesterol was 137% and erythrocyte phospholipids were 148% of levels in the rats fed 27 mg/kg iron. The fatty acid data suggest a mild impairment in essential fatty acid metabolism in moderately iron-deficient rats. The lipid data suggest a significant alteration in the total lipid content of plasma and erythrocytes of iron-supplemented rats.

Animals↗

PubMed1987

Abnormalities of plasma and erythrocyte essential fatty acid composition in epidermolysis bullosa: influence of treatment with diphenylhydantoin.

The fatty acid composition of plasma and erythrocyte phospholipids was determined in children with various subtypes of epidermolysis bullosa (EB) and in their parents. Patients with recessive dystrophic, dominant dystrophic, simplex, or junctional forms of EB had a higher percentage composition of arachidonic acid in plasma and/or erythrocyte phospholipids compared to age-matched controls. Epidermolysis bullosa patients treated with diphenylhydantoin had lower levels of arachidonic acid in plasma and erythrocyte phospholipids than did untreated EB patients. Parents of children with the recessive dystrophic or junctional EB subtypes had higher linoleic and arachidonic acids in plasma and erythrocyte phospholipids than did controls. Plasma and erythrocyte total lipids were within the normal range in children with EB. Plasma zinc was also normal but plasma copper was elevated in children with recessive dystrophic EB. We conclude that higher arachidonic acid in plasma and erythrocytes may be related to the pathology of EB.

Adult↗

PubMed1987

Long-term ethanol consumption in the hamster: effects on tissue lipids, fatty acids and erythrocyte hemolysis.

Male Golden Syrian hamsters at 1 year of age were given a basal diet and either distilled water or 10% absolute ethanol in distilled water to drink for 1 year in order to determine the influence of prolonged ethanol intake on tissue long chain fatty acid, lipid composition and erythrocyte hemolysis in response to osmotic stress. Total lipids were extracted from liver, heart, plasma and erythrocytes. Individual lipid fractions were quantitated and the percentage fatty acid composition of the lipid fractions analyzed by gas-liquid chromatography. Although no significant changes in tissue lipid content or erythrocyte hemolysis were attributable to ethanol intake, fatty acid changes were marked in the ethanol-fed hamsters. The primary fatty acid changes were increased oleic acid (40-50%) and decreased linoleic acid (25-60%) which were observed in all tissues. Arachidonic acid was decreased only in triacylglycerol fractions. The results suggest that in the hamster long-term voluntary ethanol intake alters specific long chain fatty acids, but that erythrocyte membrane integrity and tissue lipid composition were not compromised.

Alcohol Drinking↗

PubMed1986

n-3 Essential fatty acids decrease weight gain in genetically obese mice.

1. Lean (ln/ln) and obese (ob/ob) mice were given diets containing a fat source of 100 g evening primrose (Oenothera biennis) oil (fatty acids 18:2n-6, 18:3n-6; EPO) or 100 g cod liver oil (20:5n-3, 22:6n-3; CLO)/kg diet. 2. Weight gain was lower in the ob/ob mice fed on CLO, an effect unrelated to food intake. 3. In the ob/ob mice fed on CLO, thromboxane synthesis by clotting platelets was reduced compared with that in ob/ob mice fed on EPO. 4. The ob/ob CLO-fed mice had lower arachidonic acid but higher levels of n-3 fatty acids in liver, brown adipose tissue and white adipose tissue. 5. The n-3 fatty acids in CLO therefore replaced the n-6 fatty acids in tissue lipids and reduced synthesis of '2 series' prostaglandins in addition to causing lower weight gain in the CLO-fed ob/ob mice.

Animals↗

PubMed1986

Lipid and fatty acid composition of organs from copper-deficient mice.

Experiments were conducted to study the total lipid and fatty acid composition of liver, kidney, brain and heart of 7-wk-old male C57BL mice. Dietary copper deficiency was initiated at birth by feeding dams a purified diet containing 0.5 mg/kg copper. Offspring were fed the copper-deficient diet 4 wk postweaning. Control dams and offspring were fed the same diet but with added copper in the drinking water, 20 mg/L. Compared with controls the copper-deficient mice exhibited hepatomegaly, cardiac hypertrophy and a 4% reduction in brain weight as well as low ceruloplasmin activity (0.5% of control). Total phospholipid concentration in liver and kidney and total triacylglycerol concentration in kidney was lower in copper-deficient mice compared to concentrations measured in liver and kidney of control mice. The major change in essential fatty acid composition in the copper-deficient mice which was consistent between organs and lipid classes was a significantly lower proportion and absolute amount of dihomo-gamma-linolenic acid. Other changes in fatty acid composition were variable.

Animals↗

PubMed1985

Magnesium deficiency in the rat increases tissue levels of docosahexaenoic acid.

The effects of magnesium deficiency on tissue levels of total lipids and fatty acids were evaluated. Sprague-Dawley rats were fed a magnesium-deficient diet for 14 wk with controls being pair-fed to the deficient rats. Compared to the controls, serum and 24-h urinary magnesium levels were markedly lower in the magnesium-deficient rats. Serum cholesterol and total phospholipids were significantly higher in the magnesium-deficient rats than in the controls. Edema and polycystic degeneration of the kidneys were present in the magnesium-deficient rats. Kidney total phospholipids and triacylglycerols were significantly lower in the magnesium-deficient rats than in the controls. The main change in tissue fatty acid composition in magnesium deficiency was the higher docosahexaenoic acid (22:6n-3) in serum, liver and aorta than in controls. The possible relationship of these findings to human alcoholism is discussed.

Animals↗