title: Antibody against low density lipoprotein receptor blocks uptake of low density lipoprotein (but not high density lipoprotein) by the adrenal gland of the mouse in vivo.
abstract: The adrenal gland of the mouse takes up intravenously administered 125I-labeled human low density lipoprotein (LDL) by a high affinity, receptor-mediated mechanism. Uptake is enhanced by treatment of mice with a combination of 4-aminopyrazolopyrimidine, which eliminates endogenous mouse lipoproteins from the plasma, and adrenocorticotropin, which increases the number of adrenal LDL receptors. In the current studies, we show that adrenal uptake of 125I-LDL is blocked when the mice have received a prior intravenous injection of a rabbit antibody directed against the LDL receptor purified from bovine adrenal cortex. The antibody-mediated inhibition of 125I-LDL uptake persisted for 6 h and was reversed by 19 h. Adrenal uptake of 125I-labeled high density lipoprotein was not affected by the antibody, supporting the previous suggestion that high density lipoprotein uptake by the adrenal gland is mediated by a receptor that differs from the LDL receptor. The current studies illustrate the usefulness of antibodies in probing the process of receptor-mediated endocytosis in intact animals.
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism*; D000818:Animals; D000936:Antigen-Antibody Complex; D001692:Biological Transport; D005260:Female; D006801:Humans; D007074:Immunoglobulin G; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011973:Receptors, LDL; D013329:Structure-Activity Relationship
chemical_list: D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D011956:Receptors, Cell Surface; D011973:Receptors, LDL