Receptors for insulin-like growth factors I and II: autoradiographic localization in rat brain and comparison to receptors for insulin

Journal Article · Sat Oct 01 00:00:00 EDT 1988 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-123-4-2089· OSTI ID:7095803

Lesniak, M A; Hill, J M; Kiess, W; Rojeski, M; Pert, C B; Roth, J

Receptors for insulin-like growth factor I (IGF-I) in rat brain were visualized using autoradiography with (125I)IGF-I. The binding of the labeled peptide was competed for fully by high concentrations of unlabeled IGF-I. At intermediate concentrations of unlabeled peptide the binding of (125I)IGF-I was competed for by unlabeled IGF-I more effectively than by IGF-II or insulin, which is typical of receptors for IGF-I. Essentially every brain section shows specific binding of IGF-I, and the pattern of binding of IGF-I to its receptors correlated well with the cytoarchitectonic structures. In parallel studies we showed that (125I)IGF-II was bound to tissue sections of rat brain and that the binding was competed for by an excess of unlabeled IGF-II. However, intermediate concentrations of unlabeled peptides gave inconclusive results. To confirm that the binding of (125I)IGF-II was to IGF-II receptors, we showed that antibodies specific for the IGF-II receptor inhibited the binding of labeled IGF-II. Furthermore, the binding of the antibody to regions of the brain section, visualized by the application of (125I)protein-A, gave patterns indistinguishable from those obtained with (125I)IGF-II alone. Again, the binding was very widely distributed throughout the central nervous system, and the patterns of distribution corresponded well to the underlying neural structures. Densitometric analysis of the receptors enabled us to compare the distribution of IGF-I receptors with that of IGF-II receptors as well as retrospectively with that of insulin receptors.

• Research Organization: National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, MD (USA)
• OSTI ID: 7095803
• Journal Information: Endocrinology; (United States), Vol. 123:4
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GROWTH FACTORS
RECEPTORS
INSULIN
BIOLOGICAL LOCALIZATION
ANTIBODIES
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BRAIN
COMPARATIVE EVALUATIONS
INHIBITION
IODINE 125
RATS
SPECIFICITY
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MITOGENS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques