Effect of insulin and glucocorticoids on glucose transporters in rat adipocytes

Journal Article · Wed Apr 01 04:00:00 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), Journal Name: Am. J. Physiol.; (United States) Vol. 252:4; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

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