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.
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of Biological Chemistry|
|State||Published - Dec 1 1981|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology