Colocalization of vascular endothelial growth factor (vascular permeability factor) and insulin in pancreatic islet cells.
Previously, we found that the islet of pancreas stained with a antibody against the vascular permeability factor (VPF; also known as vascular endothelial growth factor, VEGF) protein. To determine how common this reaction was and whether it was a specific reaction for the islet, we examined its expression and specific cellular localization. Two different antibodies directed against VPF/VEGF peptide revealed an intense reaction for beta-cells in the human islets of Langerhans, and several human beta-cell tumors (insulinomas), but no reaction, were detectable in the vascular endothelium. In the fetal pancreas (second and third trimesters), the VPF/VEGF peptide was detected in immature islets. Northern blot analysis of cell lines derived from rodent insulinomas revealed expression of VPF/VEGF messenger ribonucleic acid. Western blot analysis of conditioned medium from one of these cell lines showed the presence of the released VPF/VEGF protein. These findings indicate that beta-cells have a specific role other than endocrine function in the pancreas. VPF/VEGF in beta-cells may be involved in the maintenance and control of permeability within the islet capillary system.
Kuroda
M
M
Department of Pathology, Faculty of Medicine, University of Tokyo, Japan.
Oka
T
T
Oka
Y
Y
Yamochi
T
T
Ohtsubo
K
K
Mori
S
S
Watanabe
T
T
Machinami
R
R
Ohnishi
S
S
D000328:Adult; D001483:Base Sequence; D015152:Blotting, Northern; D016228:Endothelial Growth Factors / Q000378:metabolism*; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000378:metabolism*; D008222:Lymphokines / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D014018:Tissue Distribution; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D007328:Insulin; D008222:Lymphokines; D015335:Molecular Probes; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors