Insulin-stimulated conversion of D-(5-/sup 3/H) glucose to /sup 3/HOH in the perifused isolated rat adipocyte

Journal Article · Wed Oct 01 00:00:00 EDT 1986 · Metab., Clin. Exp.; (United States)

DOI:https://doi.org/10.1016/0026-0495(86)90053-3· OSTI ID:6934764

Duckworth, W C; Peavy, D E; Frechette, P; Solomon, S S

Characteristics of basal and insulin-stimulated glucose utilization by perifused adipocytes have been investigated by measuring the formation of /sup 3/HOH from D-(5-/sup 3/H) glucose. At a glucose concentration of 0.55 mmol/L, basal glucose utilization ranged from 0.5 to 1.0 nmol/min/10(6) cells. Perifused adipocytes showed a maximal response to insulin of a threefold to fourfold increase in the conversion of (5-/sup 3/H) glucose to /sup 3/HOH with a half-maximal response at an insulin concentration of 20 microU/mL. The response to insulin was blocked by phlorizin and cytochalasin B, competitive inhibitors of glucose transport, consistent with an effect of insulin on glucose transport. Insulin increased the Vmax for glucose metabolism but had no effect on the apparent affinity for glucose utilization. The characteristics of glucose utilization and the stimulation of glucose metabolism by insulin in the perifused adipocyte are therefore similar to characteristics previously observed with incubated adipocytes. Because insulin can readily be removed from the system, perifused adipocytes are especially suited for studying the termination of insulin action. The termination of insulin-stimulated glucose metabolism occurred at the same rate in the presence of tracer (1 nmol/L) (5-/sup 3/H)-glucose alone as when 0.55 mmol/L glucose or 2 mmol/L pyruvate were added to the perifusion buffer. The halftime for this process in both cases was approximately 40 minutes. These data suggest that the presence of metabolizable substrate is not required for the termination of the insulin response, but the time course suggests that termination requires more than simply insulin-receptor dissociation.

• Research Organization: Veterans Administration Medical Center, Indianapolis, IN
• OSTI ID: 6934764
• Journal Information: Metab., Clin. Exp.; (United States), Vol. 10
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
FAT CELLS
METABOLISM
GLUCOSE
INSULIN
BIOLOGICAL FUNCTIONS
ADIPOSE TISSUE
HYDROXIDES
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TRITIUM OXIDES
ALDEHYDES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BODY
CARBOHYDRATES
CHALCOGENIDES
CONNECTIVE TISSUE
CONNECTIVE TISSUE CELLS
FUNCTIONS
HEXOSES
HORMONES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MONOSACCHARIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PEPTIDE HORMONES
RODENTS
SACCHARIDES
SOMATIC CELLS
TISSUES
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques