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. 1975 Oct;56(4):781–791. doi: 10.1172/JCI108156

Isolation and properties of the mixed lipid micelles present in intestinal content during fat digestion in man.

C M Mansbach 2nd, R S Cohen, P B Leff
PMCID: PMC301932  PMID: 1159087

Abstract

To evaluate better the physicochemical characteristics of human fat digestion, a method was developed which allowed characterization of the bile acid-lipid mixed micelles of the aqueous phase of post-prandial duodenal fluid. Duodenal fluid was collected after a 36-g fat breakfast for two 90-min periods and for 60 min after i.v. cholecystokinin and was ultracentrifuged at 15,400,000 g-min. The aqueous phase was isolated, passed through a 200-nm filter, and the mixed micelles were concentrated by an ultrafiltration procedure using a 1.5-nm filter. The 1.5-nm retentate was eluted from Sepharose 6B columns with 1.5-nm filtrate for both preequilibration fluid and eluent. 1.5-nm filtrate approximated the monomer concentrations. Each sample was assayed for bile acid, fatty acid, lecithin, lysolecithin, protein, cholesterol, and counterions (pH, Na+, K+, Ca2+). Constituents were concentrated only on the 1.5-nm filter. On gel permeation chromatography, coincident peaks were observed for bile acid, fatty acid, lysolecithin, and cholesterol; and were eluted with a Kav range of 0.50-0.68 (corresponding to a Stokes radius of 2.3-3.5 nm). An average density of 1.25 and coincident peaks of bile acid and fatty acid were found for the mixed micelles on sucrose density gradients. The regression lines of micellar fatty acid, lysolecithin, and cholesterol vs. bile acid gave a stoichiometry of 1.4 mol fatty acid, 0.15 mol lysolecithin, and 0.06 mol cholesterol for each mole of bile acid. Mixed micelles were homogeneous in composition. These results provide direct evidence for the existence of the postprandial mixed micelle and describe several of its physicochemical properties.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ABEL L. L., LEVY B. B., BRODIE B. B., KENDALL F. E. A simplified method for the estimation of total cholesterol in serum and demonstration of its specificity. J Biol Chem. 1952 Mar;195(1):357–366. [PubMed] [Google Scholar]
  2. AMENTA J. S. A RAPID CHEMICAL METHOD FOR QUANTIFICATION OF LIPIDS SEPARATED BY THIN-LAYER CHROMATOGRAPHY. J Lipid Res. 1964 Apr;5:270–272. [PubMed] [Google Scholar]
  3. AMES B. N., DUBIN D. T. The role of polyamines in the neutralization of bacteriophage deoxyribonucleic acid. J Biol Chem. 1960 Mar;235:769–775. [PubMed] [Google Scholar]
  4. Admirand W. H., Small D. M. The physicochemical basis of cholesterol gallstone formation in man. J Clin Invest. 1968 May;47(5):1043–1052. doi: 10.1172/JCI105794. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. BORGSTROM B., DAHLQVIST A., LUNDH G., SJOVALL J. Studies of intestinal digestion and absorption in the human. J Clin Invest. 1957 Oct;36(10):1521–1536. doi: 10.1172/JCI103549. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Borgström B. The dimensions of the bile salt micelle. Measurements by gel filtration. Biochim Biophys Acta. 1965 Jul 7;106(1):171–183. doi: 10.1016/0005-2760(65)90105-0. [DOI] [PubMed] [Google Scholar]
  7. Carey M. C., Small D. M. Micelle formation by bile salts. Physical-chemical and thermodynamic considerations. Arch Intern Med. 1972 Oct;130(4):506–527. [PubMed] [Google Scholar]
  8. Carey M. C., Small D. M. The characteristics of mixed micellar solutions with particular reference to bile. Am J Med. 1970 Nov;49:590–608. doi: 10.1016/s0002-9343(70)80127-9. [DOI] [PubMed] [Google Scholar]
  9. Entressangles B., Sari H., Desnuelle P. On the positional specificity of pancreatic lipase. Biochim Biophys Acta. 1966 Dec 7;125(3):597–600. doi: 10.1016/0005-2760(66)90048-8. [DOI] [PubMed] [Google Scholar]
  10. FOLCH J., LEES M., SLOANE STANLEY G. H. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem. 1957 May;226(1):497–509. [PubMed] [Google Scholar]
  11. Feldman E. B., Borgström B. Phase distribution of sterols: studies by gel filtration. Biochim Biophys Acta. 1966 Aug 3;125(1):136–147. doi: 10.1016/0005-2760(66)90151-2. [DOI] [PubMed] [Google Scholar]
  12. Feldman E. B., Borgström B. The behavior of glyceride-fatty acid mixtures in bile salt solution: Studies by gel filtration. Lipids. 1966 Nov;1(6):430–438. doi: 10.1007/BF02532548. [DOI] [PubMed] [Google Scholar]
  13. HOFMANN A. F., BORGSTROEM B. THE INTRALUMINAL PHASE OF FAT DIGESTION IN MAN: THE LIPID CONTENT OF THE MICELLAR AND OIL PHASES OF INTESTINAL CONTENT OBTAINED DURING FAT DIGESTION AND ABSORPTION. J Clin Invest. 1964 Feb;43:247–257. doi: 10.1172/JCI104909. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. HOFMANN A. F., BORGSTROM B. Physico-chemical state of lipids in intestinal content during their digestion and absorption. Fed Proc. 1962 Jan-Feb;21:43–50. [PubMed] [Google Scholar]
  15. HOFMANN A. F. THE FUNCTION OF BILE SALTS IN FAT ABSORPTION. THE SOLVENT PROPERTIES OF DILUTE MICELLAR SOLUTIONS OF CONJUGATED BILE SALTS. Biochem J. 1963 Oct;89:57–68. doi: 10.1042/bj0890057. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. HOFMANN A. F. The behavior and solubility of monoglycerides in dilute, micellar bile-salt solution. Biochim Biophys Acta. 1963 Jun 18;70:306–316. doi: 10.1016/0006-3002(63)90754-6. [DOI] [PubMed] [Google Scholar]
  17. Hoffman N. E., Hofmann A. F. A comparison of the rate of absorption micellar and nonmicellar oleic acid. A jejunal perfusion study in man. Am J Dig Dis. 1973 Jun;18(6):489–492. doi: 10.1007/BF01076599. [DOI] [PubMed] [Google Scholar]
  18. Hoffman N. E., Simmonds W. J., Morgan R. G. A comparison of absorption of free fatty acid and alpha-glyceryl ether in the presence and absence of a micellar phase. Biochim Biophys Acta. 1971 May 4;231(3):487–495. doi: 10.1016/0005-2760(71)90116-0. [DOI] [PubMed] [Google Scholar]
  19. Hoffman N. E. The relationship between uptake in vitro of oleic acid and micellar solubilization. Biochim Biophys Acta. 1970;196(2):193–203. doi: 10.1016/0005-2736(70)90006-4. [DOI] [PubMed] [Google Scholar]
  20. Hofmann A. F., Small D. M. Detergent properties of bile salts: correlation with physiological function. Annu Rev Med. 1967;18:333–376. doi: 10.1146/annurev.me.18.020167.002001. [DOI] [PubMed] [Google Scholar]
  21. KESSLER G., WOLFMAN M. AN AUTOMATED PROCEDURE FOR THE SIMULTANEOUS DETERMINATION OF CALCIUM AND PHOSPHORUS. Clin Chem. 1964 Aug;10:686–703. [PubMed] [Google Scholar]
  22. Kratohvil J. P., Dellicolli H. T. Measurement of the size of micelles: the case of sodium taurodeoxycholate. Fed Proc. 1970 Jul-Aug;29(4):1335–1342. [PubMed] [Google Scholar]
  23. Krone C. L., Theodor E., Sleisenger M. H., Jeffries G. H. Studies on the pathogenesis of malabsorption. Lipid hydrolysis and micelle formation in the intestinal lumen. Medicine (Baltimore) 1968 Mar;47(2):89–106. doi: 10.1097/00005792-196803000-00001. [DOI] [PubMed] [Google Scholar]
  24. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  25. Lafont H., Hauton J. Is a peptidic fraction naturally associated with bile lipids? Helv Med Acta. 1973 Sep;37(2):137–141. [PubMed] [Google Scholar]
  26. Lee K. Y., Hurley D. M., Simmonds W. J. The dependence of lipid absorption in vivo on solubilized concentration. Biochim Biophys Acta. 1974 Feb 25;337(2):214–224. doi: 10.1016/0005-2760(74)90203-3. [DOI] [PubMed] [Google Scholar]
  27. MOSINGER F. PHOTOMETRIC ADAPTATION OF DOLE'S MICRODETERMINATION OF FREE FATTY ACIDS. J Lipid Res. 1965 Jan;6:157–159. [PubMed] [Google Scholar]
  28. Mansbach C. M., 2nd Complex lipid synthesis in hamster intestine. Biochim Biophys Acta. 1973 Feb 14;296(2):386–402. doi: 10.1016/0005-2760(73)90097-0. [DOI] [PubMed] [Google Scholar]
  29. NAKAYAMA F., MIYAKE H. CHOLESTEROL COMPLEXING BY MACROMOLECULAR FRACTIONS IN HUMAN GALL BLADDER BILE. J Lab Clin Med. 1965 Apr;65:638–648. [PubMed] [Google Scholar]
  30. NORMAN A. APPLICATION OF GEL FILTRATION OF BILE ACIDS TO STUDIES OF LIPID-COMPLEXES IN BILE. Proc Soc Exp Biol Med. 1964 Aug-Sep;116:902–905. doi: 10.3181/00379727-116-29403. [DOI] [PubMed] [Google Scholar]
  31. Porter H. P., Saunders D. R. Isolation of the aqueous phase of human intestinal contents during the digestion of a fatty meal. Gastroenterology. 1971 Jun;60(6):997–1007. [PubMed] [Google Scholar]
  32. STEMPFEL R. S., Jr, SIDBURY J. B., Jr STUDIES WITH THE HYDROXYSTEROID DEHYDROGENASES. I. A SIMPLIFIED METHOD FOR THE ENZYMATIC ESTIMATION OF 3- AND 17-HYDROXYSTEROIDS. J Clin Endocrinol Metab. 1964 Apr;24:367–374. doi: 10.1210/jcem-24-4-367. [DOI] [PubMed] [Google Scholar]
  33. Shankland W. The equilibrium and structure of lecithin-cholate mixed micelles. Chem Phys Lipids. 1970 Apr;4(2):109–130. doi: 10.1016/0009-3084(70)90042-3. [DOI] [PubMed] [Google Scholar]
  34. THUREBORN E. A water-soluble lipid complex obtained in the macromolecular phase by gel-filtration of human bile. Nature. 1963 Mar 30;197:1301–1302. doi: 10.1038/1971301a0. [DOI] [PubMed] [Google Scholar]
  35. Tanford C., Nozaki Y., Reynolds J. A., Makino S. Molecular characterization of proteins in detergent solutions. Biochemistry. 1974 May 21;13(11):2369–2376. doi: 10.1021/bi00708a021. [DOI] [PubMed] [Google Scholar]
  36. Van Deest B. W., Fordtran J. S., Morawski S. G., Wilson J. D. Bile salt and micellar fat concentration in proximal small bowel contents of ileectomy patients. J Clin Invest. 1968 Jun;47(6):1314–1324. doi: 10.1172/JCI105823. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Vogel W. C., Zieve L. A LECITHINASE A IN DUODENAL CONTENTS OF MAN. J Clin Invest. 1960 Aug;39(8):1295–1301. doi: 10.1172/JCI104146. [DOI] [PMC free article] [PubMed] [Google Scholar]

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