Insulin stimulates glucose transport via nitric oxide/cyclic GMP pathway in human vascular smooth muscle cells.
OBJECTIVE
In cultured human vascular smooth muscle cells, insulin increases cyclic GMP production by inducing nitric oxide (NO) synthesis. The aim of the present study was to determine whether in these cells the insulin-stimulated NO/cyclic GMP pathway plays a role in the regulation of glucose uptake.


RESULTS
Glucose transport in human vascular smooth muscle cells was measured as uptake of 2-deoxy-d-[3H]glucose, cyclic GMP synthesis was checked by radioimmunoassay, and GLUT4 recruitment into the plasma membrane was determined by immunofluorescence. Insulin-stimulated glucose transport and GLUT4 recruitment were blocked by an inhibitor of NO synthesis and mimicked by NO-releasing drugs. Insulin- and NO-elicited glucose uptake were blocked by inhibitors of soluble guanylate cyclase and cyclic GMP-dependent protein kinase; furthermore, glucose transport was stimulated by an analog of cyclic GMP.


CONCLUSIONS
Our results suggest that insulin-elicited glucose transport (and the corresponding GLUT4 recruitment into the plasma membrane) in human vascular smooth muscle cells is mediated by an increased synthesis of NO, which stimulates the production of cyclic GMP and the subsequent activation of a cyclic GMP-dependent protein kinase.
Bergandi
L
L
Department of Genetics, Biology and Biochemistry, University of Turin, Italy.
Silvagno
F
F
Russo
I
I
Riganti
C
C
Anfossi
G
G
Aldieri
E
E
Ghigo
D
D
Trovati
M
M
Bosia
A
A
D001692:Biological Transport; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009004:Monosaccharide Transport Proteins / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D009124:Muscle Proteins; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495692:SLC2A4 protein, human; D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D005947:Glucose