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Biomedical subjects

F A Kummerow

Publications and source records attributed to F A Kummerow.

At least 91 records · Page 5Linked to original sources
PubMed1985

Comparative study of the atherogenecity of dietary trans, saturated and unsaturated fatty acids on swine coronary arteries.

Three groups of two-month-old swine were fed on basal diets supplemented with either oleic acid-rich safflower oil, lard or hydrogenated soybean oil in order to monitor the atherogenecity of various dietary fatty acids. The level of plasma triglyceride was highest in the safflower oil group and the level of plasma cholesterol was highest in the lard group. The degree of intimal thickening of the coronary arteries was most severe in the safflower oil group and lease severe in the hydrogenated fat group. Both the lard- and safflower oil-supplemented groups displayed lipid-rich coronary arterial lesions. The thickened intima of these two groups contained numerous activated smooth muscle cells, degenerated cells with or without stainable lipid and abundant cell debris. Cellular changes were less conspicuous in the coronary arteries from the hydrogenated fat group than in those from the other two groups.

Adipose Tissue↗
PubMed1985

Relationship of plasma estradiol and progesterone levels to egg productivity in domestic chicken hens.

Female chickens from eight different genetic stocks, ranging from 13 to 21 months of age, and exhibiting various levels of egg production were studied. Plasma samples were collected between 1700 and 2200 hr to determine basal circulating levels of progesterone (P4) and 17 beta-estradiol (E2) by radioimmunoassay. Linear regression analysis was used to describe the relation between mean hormone levels (E2, P4, and E2/P4) and mean egg production from these groups, and correlation coefficients were used to evaluate the general usefulness of these hormone parameters for estimating egg production within a group or flock of hens. Of the three hormone parameters evaluated, basal circulating E2/P4 was found to be the best estimator of egg productivity.

Animals↗
PubMed1984

Effect of dietary fats on desaturase activities and the biosynthesis of fatty acids in rat-liver microsomes.

Four groups of rats were fed diets containing 15% (w/w) high-oleic safflower oil (SFO, rich in cis-18:1 acids), a mixture of 80% partially hydrogenated soybean oil plus 20% corn oil (H + CO, rich in trans-18:1 acids), lard (L, rich in saturated fatty acids) and corn oil (Co, rich in 18:2 omega 6). Fatty acid composition of liver microsomes and activities of the delta 5, delta 6 and delta 9 desaturases were determined. Microsomal delta 6 desaturase activity and arachidonic acid were lower in the H + CO group compared with SFO of L. No difference was found in the delta 5 or delta 6 desaturase activity of CO and SFO groups. Thus, the oleic-acid level of the SFO diet had no effect on the metabolism of 18:2 omega 6. Fluorescent polarization studies, using trans-parinaric acid as a probe, showed no differences between the physical states of phospholipid vesicles made from lipids isolated from each group. We concluded that the trans-18:1 acids in partially hydrogenated soybean oil have a more inhibitory effect than saturated acids on EFA metabolism, even in the presence of adequate amounts of essential fatty acid.

Animals↗
PubMed1984

Plasma sex hormone and lipid patterns in normal and restricted-ovulator chicken hens.

The relationships of circulating estradiol, estrone, and progesterone levels to plasma lipid levels and ovulatory frequency were studies in sexually mature hens. New Hampshire X Columbian (NH X C) cross-bred hens, which have a relatively low frequency of ovulation, were compared with pure-bred White Leghorn (WLH) hens with a high frequency of ovulation. A mutant strain of WLH hen, exhibiting the phenotypic characteristic of restricted ovulation (RO) was also tested. It was fund that NH X C hens had a basal circulating estrogen: progesterone ratio 2.7 X greater than WLH hens. Furthermore, WLH-RO hens exhibited 3 X HIGHER BASAL PLASMA ESTROGEN AND 4 X lower progesterone than normal WLH hens, resulting in an estrogen:progesterone ratio which was l2.6X higher. In additional, WLH-RO hens did not exhibit any diurnal variation in circulating progesterone levels, and had smaller primary sex organs and also intermittent hyperlipidemia. It is concluded that the basal circulating estrogen:progesterone ratio in sexually mature hens is a good indicator of ovulatory frequency, and that the magnitude of the ratio is determined primarily by the progesterone component.

Aging↗
PubMed1984

Ultrastructural changes in the comb and aorta of chicks fed excess testosterone.

The mode of cellular response to testosterone was monitored in the combs and aortas of chicks with the aid of an electron microscope. A 7-week treatment of 30 mg of testosterone per day had little effect on plasma lipid metabolism. However, this treatment resulted in the activation of fibroblasts in the comb, activation of fibroblast-like and smooth muscle cells in the aorta, and degeneration of smooth muscle cells in the aorta. A treatment of 150 mg of testosterone per day for 7 weeks induced hyperlipidemia and lipid-rich aortic lesions. The abdominal aorta had more activated and degenerated smooth muscle cells, with or without stainable lipid droplets, than the ascending aorta.

Animals↗
PubMed1984

Comparative plasma lipid response of pullets and laying hens to estradiol and progesterone.

The effects of estradiol and progesterone treatment on plasma hormone and lipid concentrations were measured in laying hens and sexually immature pullets. Pullets and hens were divided into three groups and injected with estradiol (1 mg/kg bw), progesterone (4 mg/kg bw), or vehicle (propylene glycol) once each day for 14 days. Blood samples were collected before treatment and 24 hr after the 7th and 14th treatments. Plasma progesterone (P), estradiol (E2), triglycerides (TG), cholesterol (C), and phospholipids (PL) were measured. E2 treatments elevated hen plasma TG 7.2X, PL 5.1X, and C 7.2X; and pullet plasma TG 6.8X, PL 3.7X, and C 2.5X. However, because hen plasma was initially mildly hyperlipidemic, the E2-treated hens developed severe hyperlipidemia, but egg production was unaffected. Progesterone treatments of pullets had little or no effect on plasma lipids, but progesterone treatment of hens significantly reduced initial plasma TG and PL and also reduced egg production. No substantial differences were found in circulating E2 or P in hormone-treated hens and pullets, which indicated no extreme differences in plasma hormone clearance rates. These results indicate that long-term rather than short-term hepatic priming may account for observed differences in layer and pullet response to estradiol treatment.

Animals↗
PubMed1984

The influence of dietary isomeric and saturated fatty acids on atherosclerosis and eicosanoid synthesis in swine.

Weanling swine were fed for 6 months high fat diets containing as fat source, a high oleic acid safflower oil, lard, or a partially hydrogenated soybean oil blended with soybean oil. The extent of atherosclerosis in left coronary arteries and the ability of vascular components to synthesize eicosanoids important for blood clotting were determined. There was no significant difference (p greater than 0.05) in the extent of atherosclerosis or the synthesis of thromboxane A2. Significant effects were observed on serum cholesterol, which was elevated in the lard fed group, serum triacylglycerol, which was highest in the safflower oil group, and prostacyclin synthesis, which was depressed in both the lard and hydrogenated soybean oil diets compared to the safflower oil diet. No unique effect on the development of heart disease appears to be attributable to hydrogenated fats. The hydrogenated fat was similar to lard in decreasing prostacyclin synthesis, suggesting that the saturation of dietary fatty acids may be a contributory factor in the development of heart disease, through its effect on thrombotic processes.

Adipose Tissue↗
PubMed1984

Electron microscopic comparison of the tunica media of the thoracic aorta between species.

Previous observations indicate that the tunica media of the thoracic aorta of chickens contains two populations of cells (smooth muscle cells and connective tissue cells), whereas that of the mammalian species only contains one cell type (smooth muscle cells). It was considered that this difference in chickens: a) might occur in other avian species; b) might be a common feature in other classes from phylum chordata which are inferior to mammalia; and c) might be a special adaptation for flying animals. In order to test these hypotheses, the cytology of the tunica media of thoracic aorta was studied in five mammals (human, pig, bat, rabbit, and rat), three avian species (chicken, turkey, and pigeon), one reptile (fresh water turtle), and one amphibian (frog). All animals exhibited smooth muscle cells in the tunica media of the aorta, but only the avian species demonstrated the second major cell type (interlamellar connective tissue cells). In the avian aorta the tunica media was composed of alternating layers of smooth muscle cells and fibroblast-like connective tissue cells separated by thick elastic lamellae. It is concluded that the presence of connective tissue cells in the tunica media of the aorta may be a distinctive characteristic of birds.

Animals↗
PubMed1984

Spontaneous aortic lesions in marine turtles.

Marine turtles were found to have gross aortic aneurysmal dilations and multiple, raised grayish-white plaques which resembled both the aortic lesions of Marfan's syndrome in humans and those induced by chemical manipulation in animals. Smooth muscle cells in these aortic lesions displayed considerable functional as well as morphological similarity in their response to environmental injury in both turtles and humans.

Animals↗
PubMed1984

Influence of dietary fats on ultrastructure and fatty acid. Composition of swine arterial tissue.

The effects of trans-fatty acid-rich and saturated acid-rich diets on the fatty acid composition and morphology of swine arterial tissues were studied. Three groups of two-month-old swine were fed either a basal diet or a basal diet containing 8.3% margarine or butter for 4 months. The most significant change observed in the fatty acid pattern was the accumulation of 18 : 2 omega 6 and the suppression of both 20 : 4 omega 6 and 22 : 4 omega 6 acids in the aortic tissues of swine fed either butter or margarine as compared to swine fed the basal diet. Also, omega 6 metabolites were significantly decreased in swine fed diets containing butter or margarine, as compared to those fed a basal diet. The group of swine which were fed either butter or margarine containing diets suffered a significant increase in intimal thickening of the coronary artery compared to those fed the basal diet. These thickened intima were characterized by the presence of modified smooth muscle cells, lipid containing cells, and degenerated cells without stainable lipids. However, there was no significant difference in the incidence and extent of intimal thickening of the coronary arteries between swine fed either of the two fat containing diets.

Animals↗
PubMed1983

The relationship of adequate and excessive intake of vitamin D to health and disease.

Vitamin D is required for intestinal calcium and phosphorus absorption, kidney functions, bone synthesis, and possible vital functions in several other target tissues. Active forms of vitamin D are generated by hydroxylations, first in the liver and second in the kidney. The requirement for vitamin D is normally met by its synthesis in the skin. Inadequate skin exposure to sunlight, dark-pigmented skin, and a northern geographical latitude make some individuals susceptible to a deficiency. In the United States, various foods are fortified with vitamin D to ensure that such deficiencies do not occur. As a result, most individuals consume and synthesize more vitamin D than they require. Vitamin D is a toxic compound, and excessive amounts can cause soft-tissue calcification. We have suggested a mechanism by which this calcification might occur. There is a narrow leeway between the amount required and that initiating tissue damage. As most individuals appear to be at risk of obtaining too much vitamin D rather than too little, we suggest that fortification of foods with vitamin D should be curtailed, preferably abolished, that excessive fortification of animal foods be reduced to the level required, and that the use of dietary supplements be restricted. Populations at risk could be monitored closely and counseled to prevent vitamin D deficiency.

Adult↗
PubMed1983

Effect of excess dietary lysine on plasma lipids of the chick.

Feeding diets with 4% L-lysine to the chick produces an elevation of plasma lipids which does not occur when feeding an excess of any other amino acid. Experiments were conducted to determine whether lysine-induced hyperlipidemia is secondary to the antagonistic effect of lysine on arginine or to the anorexia which accompanies lysine feeding, and in addition, whether the lysine-induced hypercholesterolemia is affected by chick age. In all experiments gain and food intake were reduced by feeding chicks 4% lysine. Plasma cholesterol and triglyceride were elevated, but high-density-lipoprotein cholesterol, as a percentage of total, was reduced. Addition of dietary arginine up to 4% failed to reverse the depression in performance and elevation of plasma lipids. Pair-feeding the control diet to the amount consumed by lysine-fed chicks did not elevate plasma lipids above control levels. Thus, lysine-induced hyperlipidemia is not mediated by the antagonistic effect of lysine on arginine nor by the effect of lysine on food intake. The high-lysine diet prevented the normal decline in plasma cholesterol expected with advancing age of chicks. Preliminary results suggested that excess lysine stimulated cholesterol biosynthesis.

Animals↗
PubMed1983

The role of 25-hydroxy-vitamin D3 in the induction of atherosclerosis in swine and rabbit by hypervitaminosis D.

Fibromuscular intimal thickening was seen in the ascending and thoracic aorta of the swine fed 62,500 IU of vitamin D3/kg of diet for three months duration; and after 3 months of vitamin D3 withdrawal, atherosclerotic lesions were found. In rabbits, pronounced aortic smooth muscle cell necrosis developed with the forced feeding of 10,000 IU vitamin D3 dissolved in corn oil/kg body weight/day for 14 days. Serum analyses indicated that blood calcium did not differ from that of animals fed corn oil alone, but that the level of serum 25-hydroxy-vitamin D3 measured by HPLC was 30 times that in the control animals. These data suggest that choleclaciferol (the oxidized sterol with vitamin D3 activity) has a very destructive influence on the integrity of arterial wall, and that smooth muscle cell necrosis could be caused by enhanced membrane permeability to Ca2+ following 25-hydroxy-vitamin D3 incorporation into smooth muscle cell membranes.

Administration, Oral↗
PubMed1983

Modification of cell membrane composition by dietary lipids and its implications for atherosclerosis.

Dietary lipids can modify the properties of cell membranes, including membrane fluidity and membrane permeability. The saturation and isomerization of dietary fatty acids may affect the pattern of fatty acids acylated to glycerol in phospholipids. Oxidized sterols may affect membrane properties directly by their insertion in the membrane or indirectly through their effects on lipid metabolism. The flow of calcium and other nutrients into the cells appears to be a major property affected by those changes in lipid composition of membranes and may be important in the onset of atherosclerosis. The factors that alter the character of the lipids in cell membranes should receive increased study in both in vitro and in vivo systems to clarify their role in diseases processes.

Animals↗
PubMed1982

Excess dietary lysine induces hypercholesterolemia in chickens.

Lysine and arginine supplements were fed to 5-day-old chicks to test whether they would develop hypercholesterolemia in response to excess lysine in a fashion similar to mammals. Chicks developed hypercholesterolemia with a 4-5% lysine but not with arginine supplementation. These results indicate the lysine induced hypercholesterolemia is not due to anaplerotic interactions of arginine and lysine with the urea cycle.

Animals↗