Regulation of insulin-like growth factor II receptors by growth hormone and insulin in rat adipocytes

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.11.3619· OSTI ID:5356522

Loennroth, P; Assmundsson, K; Eden, S; Enberg, G; Gause, I; Hall, K; Smith, U

The acute and long-term effects of growth hormone (GH) on the binding of insulin-like growth factor II (IGF-II) were evaluated in adipose cells from hypophysectomized rats given replacement therapy with thyroxine and hydrocortisone and in cells from their sham-operated littermates. After the cells were incubated with insulin and/or GH, the recycling of /sup 125/I-labeled IGF-II receptors was metabolically inhibited by treating the cells with KCN. IGF-II binding was 100 +/- 20% higher in cells from GH-deficient animals when compared with sham-operated controls. These GH-deficient cells also showed an increased sensitivity for insulin as compared with control cells (the EC/sub 50/ for insulin was 0.06 ng/ml in GH-deficient cells and 0.3 ng/ml in control cells.). However, the maximal incremental effect of insulin on IGH-II binding was reduced approx. = 27% by hypophysectomy. GH added to the incubation medium increased the number of IGF-II binding sites by 100 +/- 18% in cells from hypophysectomized animals. This increase was rapidly induced, but the time course was slower than that for the stimulatory effect of insulin. Half-maximal effect of GH on IGF-II binding was obtained at approx. = 30 ng/ml. Thus, GH added in vitro exerted a rapid insulin-like effect on the number of IGH-II receptors. GH also appears to play a regulating role for maintaining the cellular number of IGH-II receptors and, in addition, modulates the stimulatory effect of insulin on IGF-II binding.

• Research Organization: Sahlgren's Hospital, Gothenburg, Sweden
• OSTI ID: 5356522
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:12; ISSN PNASA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CELL DIFFERENTIATION
CHEMISTRY
CONNECTIVE TISSUE CELLS
CORTICOSTEROIDS
DOSE-RESPONSE RELATIONSHIPS
FAT CELLS
GLUCOCORTICOIDS
GROWTH FACTORS
HORMONES
HYDROCORTISONE
HYDROXY COMPOUNDS
INSULIN
KETONES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MITOGENS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PEPTIDE HORMONES
PITUITARY HORMONES
PREGNANES
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SOMATIC CELLS
STEROID HORMONES
STEROIDS
STH
THYROID HORMONES
THYROXINE
VERTEBRATES