Low density lipoprotein receptor-binding activity in human tissues: Quantitative importance of hepatic receptors and evidence for regulation of their expression in vivo

Journal Article · Tue May 01 00:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.9.3469· OSTI ID:5393974

Rudling, M J ^[1]; Reihner, E; Einarsson, K; Ewerth, S; Angelin, B ^[2]

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1. Karolinska Instituet at Huddinge University Hospital (Sweden) Karolinska Institutet, Stockholm (Sweden)
2. Karolinska Institutet at Huddinge University Hospital (Sweden)

The heparin-sensitive binding of {sup 125}I-labeled low-density lipoprotein (LDL) to homogenates from 18 different normal human tissues and some solid tumors was determined. The binding to adrenal and liver homogenates fulfilled criteria established for the binding of LDL to its receptor--namely, (i) saturability, (ii) sensitivity to proteolytic destruction, (iii) inhibition by EDTA, and (iv) heat sensitivity. When the binding of {sup 125}I-labeled LDL was assayed at a constant concentration, the adrenal gland and the ovary had the highest binding of normal tissues. The highest binding per g of tissue overall was obtained in homogenates of a gastric carcinoma and a parotid adenoma. When the weights of the parenchymatous organs were considered, the major amount of LDL receptors was contained in the liver. To study the possible regulation of hepatic LDL-receptor expression, 11 patients were pretreated with cholestyramine. Increased binding activity was obtained in homogenates from liver biopsies from the cholestyramine-treated patients as compared with 12 untreated controls. It is concluded that the liver is the most important organ for LDL catabolism in humans and that the receptor activity in this organ can be regulated upon pharmacologic intervention. Further studies are needed to confirm the possibility that certain solid tumors can exhibit high numbers of LDL receptors.

• OSTI ID: 5393974
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:9; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
LIPOPROTEINS
RADIORECEPTOR ASSAY
RECEPTORS
MOLECULAR BIOLOGY
ADIPOSE TISSUE
ADRENAL GLANDS
IN VIVO
INTESTINES
IODINE 125
LIVER
MAN
MUSCLES
NEOPLASMS
OVARIES
THYROID
TISSUES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CONNECTIVE TISSUE
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE GLANDS
FEMALE GENITALS
GASTROINTESTINAL TRACT
GLANDS
GONADS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIPIDS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PRIMATES
PROTEINS
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques