Effect of insulin and glucocorticoids on glucose transporters in rat adipocytes

Journal Article · Wed Apr 01 00:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5877938

Carter-Su, C; Okamoto, K

The ability of glucocorticoids to modify the effect of insulin on glucose (L-1-/sup 3/H(N))glucose and D-(/sup 14/C-U)glucose) transport was investigated in both intact isolated rat adipocytes and in membranes isolated from hormone-treated adipocytes. In intact adipocytes, dexamethasone, a potent synthetic glucocorticoid, inhibited insulin-stimulated 3-O-methylglucose transport at all concentrations of insulin tested. Insulin sensitivity, as well as the maximal response to insulin, was decreased by dexamethasone in the absence of a change in /sup 125/I insulin binding. The inhibition was observed regardless of which hormone acted first, was blocked by actinomycin D, and resulted from a decrease in V/sub max/ rather than an increase in K/sub t/ of transport. In plasma membranes isolated from insulin-treated adipocytes, glucose transport activity and the amount of glucose transporter covalently labeled with (/sup 3/H)cytochalasin B were increased in parallel in a dose-dependent fashion. The amount of labeled transporter in a low-density microsomal fraction (LDMF) was decreased in a reciprocal fashion. In contrast, addition of dexamethasone to insulin-stimulated cells caused decreases in both transport activity and amount of labeled transporter in the plasma membranes. This was accompanied by a small increase in the amount of (/sup 3/H)cytochalasin B incorporated into the glucose transporter in the LDMF. These results are consistent with both insulin and glucocorticoids altering the distribution of glucose transporters between the plasma membrane and LDMF, in opposite directions.

• Research Organization: Univ. of Michigan Medical School, Ann Arbor
• OSTI ID: 5877938
• Journal Information: Am. J. Physiol.; (United States), Vol. 252:4
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GLUCOSE
UPTAKE
INSULIN
RADIOASSAY
LABELLED COMPOUNDS
MEMBRANE TRANSPORT
BIOCHEMICAL REACTION KINETICS
ADIPOSE TISSUE
CELL MEMBRANES
DEXAMETHASONE
GLUCOCORTICOIDS
IODINE 125
MICROSOMES
RATS
SOMATIC CELLS
TRITIUM COMPOUNDS
ADRENAL HORMONES
ALDEHYDES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CONNECTIVE TISSUE
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HEXOSES
HORMONES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KETONES
KINETICS
MAMMALS
MEMBRANES
MONOSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
PEPTIDE HORMONES
PREGNANES
RADIOISOTOPES
REACTION KINETICS
RODENTS
SACCHARIDES
STEROIDS
TISSUES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics