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Biomedical subjects

F A Kummerow

Publications and source records attributed to F A Kummerow.

At least 109 records · Page 6Linked to original sources
PubMed1982

Influence of dietary sex hormones on chick lipid metabolism.

The major ovarian hormones (estradiol and progesterone), the major testicular hormone (testosterone), and the major precursor to steroid hormones (cholesterol) were fed ad libitum in various combinations for either 2 weeks or 2 months (56 days) to 5-day-old female chicks; the effects of these treatments on liver lipids and plasma lipoproteins were measured. After two weeks, chicks fed basal diet supplemented with 0.05% estradiol had significant increases in plasma total cholesterol, triglycerides, and phospholipids (P less than .01). The combined supplementation of 0.05% estradiol plus 1% cholesterol produced an additive increase in plasma total cholesterol resulting in levels higher than obtained by either treatment alone (P less than .01). The addition of 0.2% progesterone to the 1% cholesterol diet inhibited the accumulation of plasma cholesterol (P less than .05), liver cholesterol (P less than .01), and liver triglycerides (P less than .01), which were found in comparable animals fed only 1% cholesterol. Likewise, the addition of 0.2% progesterone to diet containing 0.05% estradiol inhibited (P less than .01) accumulations in all of the plasma lipid classes which were found in comparable birds fed only 0.05% estradiol. After 2 months feeding, 0.1% testosterone had no effect on plasma or liver lipids. The combination of 0.05% estradiol plus 0.1% testosterone for 2 months was not very effective in reducing the hyperlipidemia caused by estradiol alone, but this treatment did result in a peculiar dwarf chicken. The results demonstrate strong steroid sex hormone interactions which produce major changes in chick plasma and liver lipid metabolism.

Animals↗
PubMed1981

Degenerative changes in endothelial and smooth muscle cells from aging swine ductus arteriosus and venosus.

Degenerative changes in endothelial and smooth muscle cells from fetal, 2-month-, and 6-month-old swine ductus vasculature were observed. In fetal ductus, a discontinuous internal elastic lamina and increased extracellular mucopolysaccharide deposition were initially noted. At 2 months of age, there was widespread fibromuscular intimal thickening, the appearance of modified smooth muscle cells, increased medial fibrosis, and the occurrence of cell debris and nuclear pyknosis. Early modification of smooth muscle cells was marked by increased occurrence of lysosomes, widely dilated rough endoplasmic reticulum, and Golgi bodies. Abundant aggregates of Weibel-Palade bodies occurred in early endothelial cell degeneration. At 6 months of age, after complete anatomical closure, there was abundant lipid vacuole production by degenerated medial smooth muscle cells. This study demonstrates that at various stages of occlusion, endothelial and smooth muscle cells from ductus vasculature exhibit morphological changes which are qualitatively similar to atherosclerosis.

Aging↗
PubMed1980

Plasma lipoprotein patterns in patients hospitalized for coronary artery bypass surgery.

Preoperative plasma samples from coronary artery bypass surgery patients were analyzed for relative levels of high-density lipoproteins (HDL) and low-density lipoproteins (LDL) in order to assess the HDL:LDL ratio as an indicator of risk for coronary heart disease. Fasting blood samples were drawn from bypass patients prior to surgery, and bypass patient mean plasma lipid data were compared with values from three other groups: randomly selected, newly admitted hospitalized patients; acutely ill student outpatients; and healthy hospital employees. Sudan Black B prestained plasma samples were electrophoresed on polyacrylamide gels, and HDL:LDL ratios were determined by densitometric gel scan and automatic peak integration. Of the four study groups, the bypass patient group had the lowest mean HDL:LDL ratio; the low ratios were due particularly to reduced levels of HDL2. Chemical analyses indicated that the bypass patient group also had lower mean HDL-cholesterol and higher mean total cholesterol and triglyceride levels than the other groups. When group age and sex differences were taken into account, the bypass group, especially males, also had low ratios. The results also strongly indicated that stresses involved with illness and hospitalization unrelated to clinical coronary heart disease (CHD) can adversely affect lipoprotein patterns.

Adolescent↗
PubMed1980

Coronary arterial lesions in sexually mature non-layers, layers, and roosters.

The effects of hereditary hyperlipidemia on coronary artery atherosclerosis were studied in 77 White Leghorn (DeKalb strain) chickens ranging from 4 to 13 months in age. After pubescence, the plasma levels of triglyceride and cholesterol in non-laying hens ranged 2- to 3-fold and 2- to 7-fold higher compared to layers. Serial sectioning revealed that most lesions were found in the proximal portions of both the left and right coronary arteries. Ultrastructurally, lesions in the roosters contained no foam cells, whereas some foam cells and small amounts of stainable lipid were observed in the thickened intima of layers. Half of the non-layers had stenotic lesions characterized by many foam cells, necrotic foci, and heavy stromal lipid deposits. Continuous permeation of excess plasma lipids into the arterial wall appeared to be an important factor in the development of coronary lesions.

Animals↗
PubMed1980

Morphological evidence of endogenous lipid production in swine ductus vasculature.

Specimens of ductus arteriosus and venosus from 2-month-old and 6-month-old swine were examined by electron microscope. The purpose of the study was to observe the effects of vessel closure and hypoxia on medial vascular smooth muscle cells. At 6 months of age, smooth muscle cells from the medial layer of ductus arteriosus showed signs of considerable cellular degeneration and contained lipid vacuoles which were often surrounded by granular endoplasmic reticulum. Specimens from the portal side of ductus venosus showed initial stages of smooth muscle cell degeneration and lipid vacuolization, while samples from the hepatic side of ductus venosus were nearly normal. This study contains the first reported morphological evidence of organelles in vascular smooth muscle cells which are responsible for endogenous lipid droplet production.

Animals↗
PubMed1980

Morphometrical analysis of the aging process in human arteries and aorta.

Ultrastructural and morphometrical studies were conducted on vascular tissue from 205 human Japanese specimens ranging in age from 15 weeks' gestation to 90 years. Comparison of aorta size with overall body length by allometry revealed that the aging aorta has growth and involution stages comparable to other organs, and that progressive increase in aortic diameter was the major involutional change. The cellular and extracellular components of the medial sections of thoracic and abdominal aorta, renal artery, and superior mesenteric artery were quantitated from electron micrographs and compared at different ages. It was found that the renal artery rapidly accumulated extracellular material with increasing age; in the aortic tissue, however, the peak occurrence of extracellular material occurred at pubescence. Ultrastructural studies revealed a general tendency of aging medial smooth muscle cells to transform from a smooth, rounded morphology to become irregularly shaped.

Adolescent↗
PubMed1980

Aortic lesions in nonlaying hens with endogenous hyperlipidemia.

Atherogenicity of chemically discrete cholesterol has been questioned earlier at small doses insufficient to cause hypercholesterolemia. Long-term experiments involving large doses are hindered by the propensity of cholesterol to autoxidize in air. As an alternative, aortic lesions in mature, 1- to 3-year-old laying and hereditary nonlaying hens were studied by electron microscopy. Due to spontaneous egg yolk involution, serum cholesterol values of nonlayers were high, averaging 583 mg/dL, and triglyceride values averaged 1,777 mg/dL. Respective values in layers were 106 mg/dL and 894 mg/dL. Aortic lesions in nonlayers developed earlier and were more extensive and fatty than in layers. Lipids were stainable even in the media of grossly normal segments of aorta in nonlayers. Findings suggested an important role of inhibition of hyperlipidemic components. It is unknown, however, whether large amounts of endogenous cholesterol in serum undergo autoxidation in vivo.

Animals↗
PubMed1980

Influence of an atherogenic diet on the structure of swine low density lipoproteins.

Five groups of three swine each were fed a basal diet supplemented with 15% tallow and either 0.0, 1.0, 1.5, 2.0%, or 2.5% cholesterol. The animals were studied over a period of 9 weeks to observe changes in plasma lipids and low density lipoproteins (LDL). At the end of the study period, LDL was analyzed by rate zonal ultracentrifugation, characterized chemically, and examined by differential scanning calorimetry. Within 3 weeks of initiation of the cholesterol-supplemented diets, there was an increase in the plasma levels of cholesterol and total LDL. LDL from swine fed the basal diet and the basal diet plus 1.0% cholesterol appeared in two LDL populations (LDL1 and LDL2) when analyzed by rate zonal ultracentrifugation. After diets containing 1.5, 2.0, and 2.5% dietary cholesterol, there was an increase in the mean flotation rate of total LDL which shifted to a lower density. LDL1 from the high cholesterol diets had a decreased triglyceride content when compared to those of the low cholesterol diets. When examined by differential scanning calorimetry, the LDL1 from the animals fed at least 1.5% cholesterol had phase transitions above body temperature, whereas the LDL from those fed 0 and 1.0% cholesterol had phase transitions below 37 degrees C. In contrast, the thermal behavior and fatty acid compositions of the extracted cholesteryl esters of the LDL obtained after the five different diets were not remarkably different. Since LDL triglyceride and cholesteryl esters are predicted to coexist in a common phase in the LDL core, the different thermal behavior of the LDL obtained after diets with different cholesterol contents is due to differences in triglyceride content which are a secondary effect of cholesterol-feeding. From these data we conclude that dietary cholesterol increases plasma LDL content, decreases LDL triglyceride content, and alters the particle structure. These changes in lipoprotein structure may contribute to the known development of atherosclerosis in cholesterol-fed swine.

Animals↗
PubMed1979

beta-Oxidation of the coenzyme A esters of elaidic, oleic, and stearic acids and their full-cycle intermediates by rat heart mitochondria.

beta-Oxidation rates for the CoA esters of elaidic, oleic and stearic acids and their full-cycle beta-oxidation intermediates and for the carnitine esters of oleic and elaidic acids were compared over a wide range of substrate and albumin concentrations in rat heart mitochondria. The esters of elaidic acid were oxidized at about half the rate of the oleic acid esters, while stearoyl-CoA was oxidized equally as rapid as oleoyl-CoA. The full-cycle beta-oxidation intermediates of elaidoyl-CoA (trans-16 : 1 delta 7, -14 : 1 delta 5, and -12 : 1 delta 3) were found to be oxidized at rates nearly equal to those for the corresponding intermediates of oleoyl-CoA. Therefore, after the first cycle of beta-oxidation, oleoyl-CoA and elaidoyl-CoA are oxidized at nearly equal rates. The activity of fatty acyl-CoA dehydrogenase was higher with elaidoyl-CoA and its full-cycle intermediates as substrates than with the corresponding cisisomers. It was concluded that the slower oxidation rate of elaidic acid is not due to slower oxidation of any of its full-cycle beta-oxidation intermediates, nor to slower activity of fatty acyl-CoA dehydrogenase, nor to outer mitochondrial carnitine acyltransferase. Possible explanations to account for the slower oxidation rate of elaidic acid are discussed.

Acyl Coenzyme A↗
PubMed1979

beta-Oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids by rat heart mitochondria.

Rates of beta-oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids as well as their respective cis isomers by rat heart mitochondria were measured and compared. At all concentrations studied, vaccenoyl-CoA was oxidized more rapidly than elaidoyl-CoA, but more slowly than oleoyl-CoA except at high substrate concentrations. All trans octadecenoyl-CoA esters were oxidized at a slower rate than their respective cis or saturated isomers. Oxidation rates decreased as the double bond approached the carboxyl-end.

Acyl Coenzyme A↗