Action of insulin in rat adipocytes and membrane properties

Journal Article · Tue Feb 26 04:00:00 EST 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00222a014· OSTI ID:5715433

Epand, R M; Stafford, A R; Debanne, M T ^[1]

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1. McMaster Univ., Hamilton, Ontario (Canada)

Several small peptides inhibit insulin-promoted glucose uptake in rat adipocytes. At 10 {mu}M peptide concentration, the extent of their inhibition of the insulin effect is related to the ability of these peptides to raise the bilayer- to hexagonal-phase transition temperature in model membranes. Hexane and DL-threo-dihydrosphingosine lower this phase transition temperature in model membranes, and they promote glucose uptake in adipocytes. There is thus an empirical relationship between the action of membrane additives on glucose uptake in adipocytes and their effect on the hexagonal-phase-forming tendency in model membranes. The most potent of the bilayer-stabilizing peptides tested in this work is carbobenzoxy-D-Phe-L-Phe-Gly. This peptide also inhibits insulin-stimulated protein synthesis in adipocytes. In contrast, DL-threo-dihydrosphingosine stimulates protein synthesis. The uptake of ({sup 125}I)iodinsulin by adipocytes is inhibited by carbobenzoxy-D-Phe-L-Phe-Gly. The mechanism of action of the bilayer-stabilizing peptides includes inhibition of insulin-dependent protein phosphorylation in adipocytes. The peptides are not specific inhibitors of a single function but are suggested to cause their effects by altering the physical properties of the membrane in a nonspecific manner. These results demonstrate that insulin-dependent functions of rat adipocytes can be modified by membrane additives in a manner predictable from the properties of these additives in model membranes.

• OSTI ID: 5715433
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:8; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOHYDRATES
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
FAT CELLS
GLUCOSE
HEXOSES
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MONOSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORYLATION
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SACCHARIDES
SOMATIC CELLS
TIME DEPENDENCE
UPTAKE
VERTEBRATES