The influence of treatment with polyunsaturated lecithin (EPL) and with saturated lecithin on the lipoprotein composition and fatty acid profile was investigated in 4 male chimpanzees. The animals were successively given 3 isocaloric diets containing the same amount of fat with a degree of saturation varying from 1 in the control diet to 0.2 in the diet enriched with polyunsaturated lecithin, to 4 in the diet enrich with saturated lecithin. The VLDL, LDL and HDL3 fractions were isolated by ultracentrifugal flotation; changes in their lipid and fatty acid composition were followed and their microviscosity was measured. The treatment with polyunsaturated lecithin increases the cholesterol esters and lysolecithin content in HDL3, presumably via activation of the enzyme LCAT. These modified HDL particles have a more fluid surface and a denser core and are susceptible to act as better cholesterol carriers. A complementary effect of this treatment is a decrease of the plasma triglycerides and VLDL concentration, an increase in the unsaturation ratio of the triglycerides which might take place via activation of triglyceride lipase. The saturated lecithin treatment increases the plasma VLDL and LDL concentrations and the triglyceride levels and increases mostly the saturation ratio of the cholesterol esters. These effects are likely to enhance the progression of atherosclerosis.

Thin-layer chromatography was carried out on glass rods coated with Silica gel (chromarod) and the fractions were detected with a flame ionization detector (FID). This system was applied to the fractionation and screening of plasma lipids. As the relative response of the flame ionization detector depends on the nature of the lipids, correction factors had to be introduced. These correction factors were derived from comparison of the results of the thin-layer chromatography with flame ionization detection with those obtained by conventional chemical analysis of the same sample. The coefficients of variation of the lipid profiles were comparable for both techniques. The absolute lipid concentration for the various fractions obtained by combination of the concentration of the total lipids with the relative lipid profile, correlate very well with the values obtained by conventional chemical analysis of the various lipids.

Baboon high-density lipoproteins (HDL) were isolated by preparative ultracentrifugation between d = 1.063 and 1.215 g/mL. The HDL contains 48.8% protein and a lipid distribution similar to human HDL. The phospholipid distribution shows a low sphingomyelin value (5.9%), and the fatty acid composition of HDL is comparable to the human data except for the 18:1/18:2 ratio as a result of a higher 18:1 content in the CE and a lower 18:2 concentration in the PL. The major HDL apoproteins isolated on diethylaminoethyl-cellulose had a mobility on sodium dodecyl sulfate--polyacrylamide gel electrophoresis and a molecular weight and an amino acid composition similar to human apoA-I. However, the amino acid sequence of the first 30 residues of baboon apoA-I differed from the human apoprotein in residues 15 and 21. Treatment of apoA-I with carboxypeptidase A indicated a carboxyl-terminal sequence of Leu-Ser-Thr-Gln. Baboon apoHDL contained monomeric apoA-II with the mobility of monomeric human apoA-II and a molecular weight of 8500. The amino acid composition differed from the human apoA-II by the presence of arginine and by the absence of half-cystine and isoleucine. The circular dichroic spectra of apoA-I and apoA-II demonstrated a higher helicity compared to the human apoproteins. Recombination studies by microcalorimetry of apoHDL with dimyristoylphosphatidylcholine (DMPC) indicated similarities in the thermodynamic binding properties of the HDL apoproteins from man and baboon. The maximal-binding enthalpies of DMPC to apoHDL, apoA-I, and apoA-II were lower for the baboon than for the human apoprotein.

A sensitive and practical method is described for the analysis of the proteins contained in human sweat and urine which does not require pre-concentration of the sample. Technical details are provided of the agarose-gel isotachophoresis and the proteinograms of normal and pathological urine samples, as well as proteinograms of human sweat. The method can also be applied as an electro-concentration system in a field-strength gradient. By means of this electro-concentration system, and in combination with immunodiffusion against monospecific antisera, a detection limit of albumin of 50 ng/ml has been obtained.

A novel potent vasoactive agent, 1-(4-isopropyl-thiophenyl)-2-n-octylaminopropanol (suloctidil, Sulocton), lowers excess of plasma cholesterol and tends to normalize the plasma hyperbetalipoproteinemia of Rhesus monkeys fed a high-cholesterol, high-fat diet. The drug shows an inhibitory effect on the cholesterol biosynthesis in rat liver homogenates.

The purpose of this study was to establish a relationship between self-association and phospholipid binding of the human and the baboon apoA-I protein. The enthalpy changes on binding dimyristoyl lecithin and lysolecithin to either the human or the baboon native apoA-I protein were measured in a microcalorimeter. An endothermal process, most pronounced for the human apoprotein, was observed at low phospholipid levels. At higher phospholipid to protein ratios the binding was exothermal. Gel filtration experiments on Sephadex G-200 showed that the native apoprotein of both species consists of dimers and tetramers. The baboon native apoA-I protein contained a higher amount of dimers. After preincubation of the apoA-I protein with lysolecithin, the enthalpy changes measured on subsequent binding of dimyristoyl lecithin were shifted towards more exothermal values compared to the curve for the native apoprotein. The amplitude of this shift corresponds to that of the endothermal process observed on binding dimyristoyl lecithin to the native apoprotein. This process was attributed to a phospholipid-induced disaggregation of the apoA-I protein. Gel filtration data showed a decreased extent of aggregation in the apoA-I protein preincubated with lysolecithin. This sample consisted exclusively of dimers. Ultracentrifugal flotation of the complexes formed between the apoA-I protein, and respectively dimyristoyl lecithin and sphingomyelin indicated that preincubation with lysolecithin increased the extent of complex formation. These results suggest that the dimeric form of the apoA-I protein possesses the highest affinity for phospholipids. Any dissociation of higher polymers enhances the phospholipid-binding capacity of the human and the baboon apoA-I protein.

The enthalpy changes associated with protein-lipid binding were measured in an isothermal microcalorimeter. This technique was applied to the study of the association between albumin with fatty acid and lysolecithin, and between the plasma apolipoproteins and phospholipids.

There is no dearth of experimental techniques for producing the hyperlipoproteinemia resulting in atherosclerotic complications and for myocardial infarction in the non human primates. Most of the recent experiments which have given information of great value have been studied with relatively expensive animals for a long period of time up to 6-7 years. It is evident that no animal model perfectly duplicates the human disease or satisfies all desirable requirements. The chimpanzees, representatives of the New World monkeys, have circulating plasma lipoproteins identical to man in composition as well as in function. The results reported above indicate that the compositional changes of chimpanzee plasma lipoproteins in response to dietary changes reflect the appearance of type II and type IV hyperlipoproteinemia similar to the human disease. Moreover, there are more indications about the existence of genotype II a in the chimpanzee, and also on the influence of stress on the plasma lipids, so that the developed intimal lesions similar to the human pathology are in this sense multifactorially influenced. From a phylogenetic point of view the chimpanzee is closer to man than any other non human primate. Furthermore, the chimpanzee lipoproteins are useful models for understanding the relationship between function and structure of the plasma lipoproteins in health and disease. Baboon and rhesus monkeys show similar results, but more differences to the human lipoproteins in health and disease were observed. At present it appears that the most useful models of human atherosclerosis are those induced in the non human primates, especially in the chimpanzee.

The effect of polyunsaturated phosphatidylcholine (PU-PC) on the biochemical types of hyperlipoproteinemia and, the induced changes in the individual lipoprotein classes were investigated. 350 male and female hyperlipoproteinemic patients were screened by a panel of clinical and biochemical parameters. The selected patients belonged to type IIa and b (n=55) and type IV (n=37). 16% of the cohort members had hypertension, 16% had cardiovascular complications, 23% had cerebral symptoms and 14% had peripheral atherosclerosis. 31% of the group were obese and 9% of them were diabetic. Only patients with the same hyperlipoproteinemic type taken twice at an interval of 14 days were retained for statistical evaluation. 92 patients were intravenously treated during 14 days with 100 mg PU-PC/day and 69 patients were further treated perorally with 3x2 caps/day (1800 mg/d) for 106 days.

The main objective of experimental atherosclerosis is to start in anima vili the atherogenic process in such a way as to be able to study its cause or causes, its development and its effects. However, such an ambitious program is nearly impossible to carry out if one wishes to extrapolate the experimental observations in spontaneous human atherosclerosis. Indeed, the latter is a multifactorial phenomenon in which metabolic elements play without a doubt a major but certainly not the only role.

Chromatography of serum lipids on a silicic acid column by gradient elution and with continuous detection is described. The gradient is formed in a new organic gradient device based on the principle of E. Peterson and H. A. Sober ((1959) Anal. Chem.31, 857), starting from six initial organic solvents. The detection is realized by flame ionization on a LCM2 liquid chromatography detector (Pye-Unicam). The technique is less solvent- and time-consuming and is of interest in preparative separation and analysis of lipophilic substances.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation and partial characterization of chimpanzee plasma high density lipoproteins and their apolipoproteinsV. Blaton, R. Vercaemst, N. Vandecasteele, H. Caster, and H. PeetersCite this: Biochemistry 1974, 13, 6, 1127–1135Publication Date (Print):March 1, 1974Publication History Published online1 May 2002Published inissue 1 March 1974https://pubs.acs.org/doi/10.1021/bi00703a012https://doi.org/10.1021/bi00703a012research-articleACS PublicationsRequest reuse permissionsArticle Views34Altmetric-Citations37LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

A new electrophoretic technique for the separation of serum lipoproteins on agarose is described. Based on the method and with the aid of the lipoprotein lipid values, a screening procedure for hyperlipoproteinaemias is presented. The influence of seasonal variations was investigated.

FEBS LettersVolume 44, Issue 2 p. 185-188 Full-length articleFree Access Activation of lipoprotein lipase in vitro by unsaturated phospholipids V. Blaton, V. Blaton Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this authorD. Vandamme, D. Vandamme Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this authorH. Peeters, H. Peeters Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this author V. Blaton, V. Blaton Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this authorD. Vandamme, D. Vandamme Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this authorH. Peeters, H. Peeters Simon Stevin Instituut for Scientific Research, Jerusalemstraat 34, B-8000 Brugge, BelgiumSearch for more papers by this author First published: August 25, 1974 https://doi.org/10.1016/0014-5793(74)80722-2Citations: 17AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References 1 E.A. Korn, J. Biol. Chem., 215, (1955), 15– 2 A.M. Scanu, Science, 153, (1966), 640– 3 Rosa J.C. La, R.I. Levy, P. Herbert, S.E. Lux, D.S. Frederickson, Biochem. Biophys. Res. Commun., 41, (1970), 57– 4 R. Havel, V. Shore, B. Shore, D. Bier, Circulation, 41, (1970), 6– Supple III 5 C.J. Fielding, C.T. Lim, A.M. Scanu, Biochem. Biophys. Res. Commun., 39, (1970), 889– 6 W.V. Brown, R.I. Levy, D.S. Frederickson, Biochim. Biophys. Acta., 200, (1970), 573– 7 Rosa J.C. La, R.I. Levy, W.V. Brown, D.S. Frederickson, Am. J. Physiol., 220, (1971), 785– 8 D. Ganesan, R.H. Bradford, Biochem. Biophys. Res. Commun., 43, (1971), 544– 9 J. Chung, A.M. Scanu, F. Reman, Biochim. Biophys. Acta, 296, (1973), 116– 10 V. Blaton, D. Vandamme, H. Peeters, Verhandl. Deutschen Gesellsch. f. Innere Medizin, 78, (1972), 1242– 11 V. Blaton, R. Vercaemst, N. Vandecasteele, H. Caster, H. Peeters, Biochemistry, 13, (1974), 1127– 12 S. Koga, L. Bolis, A.M. Scanu, Biochim. Biophys. Acta, 236, (1970), 416– 13 Lowry, O.H., Rosebrough, N.J., Farr, A.L., Randall, R.J. (0000) J. Biol. Chem. 193 265. 14 V.P. Dole, J. Clin. Investig., 35, (1956), 150– 15 V. Blaton, A.N. Howard, G.A. Gresham, D. Vandamme, H. Peeters, Atherosclerosis, 11, (1970), 497– 16 V. Blaton, H. Peeters, IIIrd International Symposium on Atherosclerosis, W. Berlin, (1973), In press Citing Literature Volume44, Issue2August 25, 1974Pages 185-188 ReferencesRelatedInformation