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Biomedical subjects

C C Heuck

Publications and source records attributed to C C Heuck.

At least 55 records · Page 3Linked to original sources
PubMed1980

Does parathyroid hormone play a role in lipid metabolism?

PTH activates hormone-sensitive lipolysis in adipose tissue by an adenylate cyclase mechanism. Effects on lipoprotein synthesis and catabolism are conceivable, but have not been studied in detail so far. Information on serum lipids in primary and secondary hyperparathyroidism is conflicting. Some authors find an increase of serum lipids upon administration of PTH and in patients with primary hyperparathyroidism, while others find a decrease of serum cholesterol and serum triglycerides which reverts to normal upon parathyroidectomy in patients with primary hyperparathyroidism. In experimental models of uremia, PTH clearly plays a permissive role for the development of uremic hyperlipemia. In PTX uremic animals, hyperlipoproteinemia is less marked than in PT-intact uremic animals, but serum lipids are still higher in PTX uremic animals than in nonuremic PT-intact animals. This would indicate that hyperlipemia is caused by PTH-independent mechanisms but is intensified by the presence of secondary hyperparathyroidism. The role of PTH in the hyperlipoproteinemia of uremic patients has not been clarified so far.

Adenylyl Cyclases↗
PubMed1979

[The effect of lipid level lowering diets on bile lipids and plasma lipoproteins in normal persons].

The effects of two fat-modified diets, one rich in polyunsaturated and the other in oleic acids, were studied in 10 healthy young males with regard to bile lipid composition, plasma lipids and lipoproteins. The two experimental diets were given for 2 weeks each and findings compared with those from the subject's normal diet. The fat-modified diets had marked but comparable effects on plasma total cholesterol (decreases by 23% and 16% respectively), on LDL-cholesterol (decreases by 27% and 17% respectively) and on HDL-cholesterol (decreases by 26% and 27% respectively). HDL apolipoproteins A-I and A-II were unaffected. Therefore, the apo A-I/HDL-cholesterol and apo A-II/HDL-cholesterol ratios significantly increased. The "lithogenic index" as a measure for the relationship of cholesterol to bile acids and phospholipids, and thus for the solubility of cholesterol in gallbladder bile, was not affected by the lipid lowering diets, which therefore should not increase the risk of cholelithiasis.

Adult↗
PubMed1979

Rapid development of immunoprecipitins in agarose gel.

A procedure for the rapid development of immunoprecipitins in agarose gels has been developed using polyanion precipitation after immunoelectrophoretical separations. Excellent results are obtained for serum apolipoproteins, immunoglobulins and other proteins. It is shown that quantitative determination of apolipoprotein B in hyperlipemic serum and isolated lipoproteins is affected by immunoprecipitated complexes when rocket immunoelectrophoresis is used. This effect can be avoided by addition of polyvinylpyrrolidone.

Apolipoproteins↗
PubMed1979

Blood pressure and adipose tissue linoleic acid.

In a natural, "free-living population" of 650 men, surveyed with the purpose of health assessment within an epidemiological design, a strongly significant negative correlation between the relative linoleic acid composition of adipose tissue and blood pressures was found (P less than 0.001). This correlation remained significant when age and weight were statistically controlled for. Thus, dietary, lipid-lowering linoleic acid seems to effect blood pressures as well in a favorable way.

Adipose Tissue↗
PubMed1979

Metabolic response to heavy physical exercise before and after a 3-month training period.

Twenty healthy athletes performed a heavy physical exercise before and after a controlled training period of 3 months. As a result of physical training there was a reduction in lactate concentration during and after exercise. Plasma free fatty acids and triglyceride levels were lower at rest as well as during and after exercise. Insulin concentrations decreased during exercise before the training period whereas they remained constant afterwards. The composition of individual free fatty acids changed in the same way during exercise before and after training: fatty acids with shorter hydrocarbon chains increased, those with longer chains decreased. Comparing the pattern of individual free fatty acids before and after training a higher percentage of saturated and a lower percentage of mono-unsaturated fatty acids was observed. It is concluded that changes in the plasma free fatty acid profile during heavy exercise reflect a preferential uptake and oxidation of certain individual free fatty acids. The significance of training-induced changes in the plasma free fatty acid pattern is discussed.

Adult↗
PubMed1979

Nocturnal inhibition of lipolysis in man by nicotinic acid and derivatives.

The effect of nicotinic acid and several derivatives on the nocturnal level of free fatty acids was studied in 12 healthy young women and men. Free fatty acids are an important precursor of plasma triglycerides and their concentration is highest at night. The drugs used were nictinic acid, beta-pyridyl-carbinol, mesoinositol hexanicotinate and xantinol nicotinate. The highest plasma nicotinic acid level was observed with beta-pyridyl-carbinol, but significant reduction in free fatty acids during the entire night was only achieved with inositolhexanicotinate and xantinol nicotinate. There was no correlation between the plasm levels of free fatty acids and nicotinic acid at any sampling time. If prolonged reduction in free fatty acid concentration is desired in the therapy of hyperlipidemias, the inositol and xantinol esters of nicotinic acid appear to be superior to the other preparations.

Adult↗
PubMed1979

Acute dietary effects on plasma lipids, lipoproteins and lipolytic enzymes in healthy normal males.

Diurnal plasma lipids and lipoproteins were studied in twelve healthy young males on corn oil and palm oil diets, respectively. The major triglyceridy. Lecithin-cholesterol acyl transferase, lipoprotein lipase and hepatic triglyceride lipase were also measured. diurnal changes of triglycerides and cholesterol were confined to lipoproteins of d less than 1.006 kg/l. There was a diurnal rise of lecithin-cholesterol acyl transferase activity with corn oil but not with palm oil. Fasting and postprandial postheparin lipoprotein lipase and hepatic triglyceride lipase were similar but there was a significant correlation of postprandial hepatic lipase with postprandial plasma triglycerides on palm oil. Marked diurnal changes of triglyceride fatty acids were observed not only in 'very low density lipoprotein' but also in high-density lipoprotein amounting to approximately one third of total high density lipoprotein triglyceride fatty acids.

Adult↗
PubMed1979

Nephelometry of apolipoprotein B in human serum.

We studied the development of light scattering in the reaction between anti-apolipoprotein B and apolipoprotein B in intact very-low-density lipoproteins (I) and low-density lipoproteins (II) as well as in lipoproteins treated with lipases, and found considerable differences in the kinetics of the immunoreaction for the two lipoprotein classes. Pre-incubation with triglyceride lipase and cholesterol esterase caused a decrease of final light scattering in I but only minimal changes in the reaction with II. Non-ionic detergent not only decreased the original light scattering in hyperlipemic serum samples, but also accelerated the immunoreaction. Under standardized conditions, results of quantitative nephelometry correlated highly significantly with quantitative determination of apolipoprotein B by radial immunodiffusion, both for normolipemic and hyperlipoproteinemic serum samples. The nonspecific light scattering caused by neutral lipids in intact lipoproteins could be minimized when samples were pre-incubated with lipolytic enzymes.

Apolipoproteins↗
PubMed1979

24-hour patterns of blood sugar, plasma insulin and free fatty acids in patients with primary endogenous hyperlipoproteinemia on isocaloric diets containing 30, 40 and 79 cal% carbohydrates.

10 patients with primary, endogenous hypertriglyceridemia (type IV hyperlipoproteinemia) underwent three different isocaloric dietary regimes of 10 days duration each. The diets contained either 30, 43 or 79% of calories as carbohydrate with 20% of calories from protein. Analyses of insulin, blood sugar and free fatty acids were conducted on the last day of each dietary period, at frequent intervals. There were no differences in either fasting or diurnal blood sugars with the different diets. Insulin levels were positively correlated with the amount of carbohydrate in the diet and there was an inverse correlation between the carbohydrate contents of the diets and circulating free fatty acid levels during waking hours. Since glucose tolerance is maintained, and diurnal plasma lipid levels are lowest with the low fat regime, such diets may be advantageously used for patients with endogenous hypertriglyceridemia.

Adult↗
PubMed1979

24-Hour patterns of blood sugar, plasma insulin and free fatty acids in patients with primary endogenous hyperlipoproteinemia on isocaloric diets containing 30, 43 and 79 cal% carbohydrates.

10 patients with primary, endogenous hypertriglyceridemia (type IV hyperlipoproteinemia) underwent three different isocaloric dietary regimes of 10 days duration each. The diets contained either 30, 43 or 79% of calories as carbohydrate with 20% of calories from protein. Analyses of insulin, blood sugar and free fatty acids were conducted on the last day of each dietary period, at frequent intervals. There were no differences in either fasting or diurnal blood sugars with the different diets. Insulin levels were positively correlated with the amount of carbohydrate in the diet and there was an inverse correlation between the carbohydrate contents of the diets and circulating free fatty acid levels during waking hours. Since glucose tolerance is maintained, and diurnal plasma lipid levels are lowest with the low fat regime, such diets may be advantageously used for patients with endogenous hypertriglyceridemia.

Adult↗
PubMed1978

Abnormal low density lipoproteins in children with familial hypercholesterolemia--effect of polyanion exchange resins.

In 20 children and adolescents with familial Type II a hyperlipoproteinemia, serum lipids and lipoproteins were examined before and during treatment with polyanion exchange resins. The composition of LDL was compared to that of helthy siblings. The patients were given Colestyramine (0.6 g/kg body weight) and Colestipol (0.5 g/kg body weight) in a cross-over study for 8 weeks each, after they had been under dietary treatment for at least 12 months. In 6 children, drug treatment had to be stopped due to side-effects. The most common complaints were gastrointestinal discomfort and constipation. Cholesterol, triglycerides and phopholipids were measured in whole serum and cholesterol, triglycerides and Apolipoprotein-B in isolated lipoprotein fractions after ultracentrifugation. Apo-B was determined by radial immunodiffusion. The Apo-B: cholesterol ratio in whole serum and in the LDL fraction was identical in the patients and in the controls. The LDL triglyceride: Apo-B ratio, however, was about 50% lower in the patients. This abnormal LDL composition was not altered by therapy with polyanion exchange resins. HDL cholesterol levels were significantly lower in the patients than in healthy children, and remained low during therapy. The decrease of total and LDL cholesterol (25%) and Apo-B (20%) was similar under both Colestipol and Colestyramine. Triglycerides and phospholipids showed no significant changes in therapy.

Adolescent↗
PubMed1978

Sitosterol in juvenile type II hyperlipoproteinemia.

The effect of beta-sitosterol on plasma lipids and lipoproteins was evaluated in a randomized double-blind cross-over trial in 15 children and adolescents with familial hypercholesterolemia over a period of 6 months. Twelve patients completed the study, with good adherence to drug intake. Sitosterol lowered the plasma total choelsterol by 6%, LDL cholesterol by 7% and HDL cholesterol by 15% (P less than 0.05). This insufficient response of total and LDL cholesterol and the marked fall of HDL cholesterol appears to advise against the use of beta-sitosterol granulate in juvenile type II hyperlipoproteinemia.

Adolescent↗
PubMed1978

Hyperlipoproteinemia in experimental chronic renal insufficiency in the rat.

Lipid metabolism was studied in experimental uremia. Uremic (U) rats were compared with sham-operated, pair-fed (PF) controls and with ad-lib-fed (AL) controls. In U animals, fasting glucose concentrations were normal, immunoreactive serum insulin (IRI) levels were decreased, and immunoreactive glucagon levels were increased. A significant increase in the serum concentration of all lipid classes was observed: triglycerides were elevated 10-fold above the values in PF and AL controls; phospholipids, twofold; total cholesterol, threefold; and free cholesterol, sixfold. Cholesterol concentration was increased in beta- and pre-beta-lipoproteins and even more so in alpha- and pre-alpha-lipoproteins. There was an increase in the ratio of free cholesterol/total cholesterol. The fatty acid composition of serum lipoproteins was unchanged. Concomitantly, in liver tissue, there was no change in lipid content (triglyceride, cholesterol) and fatty acid composition. These findings argue against glucose- or insulin-mediated changes in hepatic de novo fatty acid synthesis, chain elongation, or poly-desaturation. In U animals, the HMG-CoA-reductase activity of liver microsomes was slightly, but not significantly, reduced as was tritiated water incorporation into cholesterol in isolated perfused liver preparations. In adipose tissue, there was a decrease in triglyceride content. The results provide evidence against insulin-mediated hepatic overproduction as a major cause of hyperlipoproteinemia in this model of experimental renal insufficiency and point to peripheral under-utilization of lipoproteins.

Animals↗