title: Metabolism of chylomicron-like emulsions in carriers of the S447X lipoprotein lipase polymorphism.
abstract: BACKGROUND
  Lipoprotein lipase catalyzes the hydrolysis of the triglycerides contained in both very-low-density lipoproteins and chylomicrons for storage in the adipose tissue and muscle of fats of both hepatic and dietary origin. The S447X-Stop lipoprotein lipase is the most common polymorphism of the enzyme, affecting roughly 20% of the population and is accompanied by normal or diminished fasting triglycerides and perhaps lower incidence of coronary artery disease (CAD). Delay in the removal of chylomicron and remnant is now an established risk factor for CAD.
  
  
  METHODS
  Currently, the chylomicron metabolism has been evaluated in 12 normolipidemic subjects with the S447X-Stop and in 13 age- and sex-paired control subjects with no mutation. The doubly labeled chylomicron-like emulsion method was used to evaluate chylomicron metabolism. The emulsions labeled with cholesteryl-oleate (14C-CE) and tri[9,10-3H]oleate (3H-Tg) were injected intravenously and the decay curves of the labels were determined by blood sampling over 60 min followed by radioactive counting.
  
  
  RESULTS
  The fractional clearance rate (FCR, min(-1)) of the labels was not different in the S447X carriers compared with the noncarriers (FCR 3H-Tg 0.035 +/- 0.019 and 0.030 +/- 0.009; FCR 14C-CE 0.008 +/- 0.007 and 0.009 +/- 0.007, respectively).
  
  
  CONCLUSIONS
  The chylomicron intravascular lipolysis monitored by the 3H-Tg emulsion and the remnant removal monitored by the 14C-CE emulsion were not altered by the presence of this polymorphism of great populational impact.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Katia A
authors.initials: KA
authors.lastname: Almeida
authors.forename: Roberto
authors.initials: R
authors.lastname: Schreiber
authors.forename: Rosângela F
authors.initials: RF
authors.lastname: Amâncio
authors.forename: Sérgio P
authors.initials: SP
authors.lastname: Bydlowski
authors.forename: Adriana
authors.initials: A
authors.lastname: Debes-Bravo
authors.forename: Jacqueline S
authors.initials: JS
authors.lastname: Issa
authors.forename: Célia M C
authors.initials: CM
authors.lastname: Strunz
authors.forename: Raul C
authors.initials: RC
authors.lastname: Maranhão
mesh_terms: D000328:Adult; D002788:Cholesterol Esters / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D002914:Chylomicrons / Q000097:blood / Q000378:metabolism*; D004655:Emulsions; D005260:Female; D005838:Genotype; D006801:Humans; D007700:Kinetics; D008071:Lipoprotein Lipase / Q000235:genetics*; D008074:Lipoproteins / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D011110:Polymorphism, Genetic; D014280:Triglycerides / Q000097:blood
chemical_list: D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D002914:Chylomicrons; D004655:Emulsions; D008074:Lipoproteins; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D008071:Lipoprotein Lipase