Abstract
Aims/hypothesis: We aimed to characterise the development of autoregulation of glucose transport in vascular endothelial cells and its relationship to 12-lipoxygenase (12-LO) expression. Methods: Bovine aortic endothelial cells were exposed to 5.5 and 23.0 mmol/l glucose for up to 48 h. The rates of glucose transport, GLUT-1 and 12-LO expression and of 12-hydroxyeicosatetraenoic acid (12-HETE) production were determined. Results: We showed high glucose-dependent downregulation of glucose transport and transporter in vascular endothelial cells within 36-48 h. A similar time-dependent increase in the expression of 12-LO and the generation of its product 12-HETE was also observed. This downregulatory process was prevented when lipoxygenase activity was inhibited. Conclusions/interpretation: Vascular endothelial cells, which were previously thought to be "glucose-blind", do in fact downregulate GLUT-1 expression and the rate of glucose transport in response to extended exposure to high glucose concentrations. This slow development of glucose-induced downregulation in vascular endothelial cells is related to the slower basal rate of glucose transport in these cells and the slow induction of 12-LO. These data are interesting in view of current hypotheses that attribute vascular endothelial cell dysfunction in diabetes to the lack of a glucose-induced autoregulatory response.
Original language | English |
---|---|
Pages (from-to) | 752-755 |
Number of pages | 4 |
Journal | Diabetologia |
Volume | 48 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2005 |
Keywords
- Endothelial cells
- Glucose transport
- Glucose transporter
- Hydroxyeicosatetraenoic acids
- Lipoxygenase
- Lipoxygenase inhibitors
- Vascular smooth muscle