Effect of Diets with and without Fat at Low and High Caloric Levels on Fatty Acids in Blood Cells and Plasma of Dogs

Essential fatty acid deficiency during total parenteral nutrition

Essential fatty acid (EFA) deficiency has become a clinical problem since the advent of fat-free total parenteral nutrition (TPN). The following study was done to determine the minimum fat requirements for patients receiving continuous TPN solution. Seventy-seven patients who had 97 courses of TPN of at least 14 days duration were prospectively studied. The following fat supplementation was given: a) none, b) 10% soybean oil emulsion intravenously at fixed dosage, c) fat from an oral diet, or d) intravenous and oral fat. No patient was EFA deficient before the onset of TPN. EFA deficiency was prevented when at least 3.2% of total calories were given as intravenous fat or at least 15% as oral fat. Lesser amounts of fat decreased the rate of EFA deficiency development but did not prevent it from occurring. The 7.7 g/day of linoleic acid provided in 1000 ml per week of 10% soybean oil emulsion provides adequate fat to prevent EFA deficiency.

The effects of estrogen and androgen on osmotic fragility and fatty acid composition of erythrocytes in the chicken

Breed and sex differences were observed in erythrocyte counts in the chicken. A difference in osmotic fragility of erythrocytes was found between chickens of the New Hampshire and White Leghorn breeds. Erythrocytes from mature males were more susceptible to osmotic hemolysis than were erythrocytes from mature females. Lipids extracted from ghosts of erythrocytes from mature females or from males treated with diethylstilbestrol contained a higher proportion of oleic to stearic acid than did those from male birds. Incubation of erythrocytes in plasma derived from birds of the opposite sex increased the osmotic stability of ceils from males and decreased the stability of cells from females in comparison with the stability of erythrocytes incubated in autologous plasma.

LIPID PATTERN IN EXPERIMENTAL CANINE ATHEROSCLEROSIS

An experiment was conducted to compare the effects of feeding cholesterol alone, thiouracil alone, and cholesterol and thiouracil combined, on the serum lipids and arteries of dogs. These substances were added to a basal diet rich in linoleic acid. Serum cholesterol and total serum lipids were determined periodically during the four-month period of feeding, and serum and tissue lipids obtained at necropsy were fractionated and analyzed by silicic acid column and gas chromatography.

During the period of feeding the experimental diets, three levels of hypercholesterolemia and hyperlipemia were produced. The smallest increase over control levels occurred in the animals receiving cholesterol alone; an intermediate increase was produced in those receiving thiouracil alone; and the greatest increase occurred in the group receiving both cholesterol and thiouracil. The lipemia was proportional to the cholesterolemia in each of the experimental groups. Only those dogs receiving both cholesterol and thiouracil developed arterial lesions.