Comparison of methods for incorporating a radioiodinated residualizing cholesteryl ester analog into low density lipoprotein.
Two different methods were evaluated for incorporating [125I]cholesteryl iopanoate ([125I]CI), a non-hydrolyzable cholesteryl ester analog, into LDL. The first procedure was an organic solvent delipidation-reconstitution procedure (R[125I-CI]LDL) while the second involved incubation of detergent (Tween-20)-solubilized [125I]CI with whole plasma (D[125I-CI]LDL). R[125I-CI]LDL behaved similar to native LDL in vitro, but was markedly different in vivo, apparently due to a heterogeneity in particle size. D[125I-CI]LDL, however, was metabolized normally both in vitro and in vivo. These results, combined with the residualizing nature of [125I]CI, demonstrate that D[125I-CI]LDL is appropriate for tracing LDL uptake in vivo.
Deforge
L E
LE
Department of Pharmacology, University of Michigan, Ann Arbor 48109.
Degalan
M R
MR
Ruyan
M K
MK
Newton
R S
RS
Counsell
R E
RE
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002788:Cholesterol Esters / Q000493:pharmacokinetics*; D005347:Fibroblasts / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism* / Q000493:pharmacokinetics; D008077:Lipoproteins, LDL / Q000378:metabolism* / Q000493:pharmacokinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D013961:Thyroid Gland / Q000378:metabolism; D014018:Tissue Distribution
D002788:Cholesterol Esters; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL; C039133:cholesteryl iopanoate