| Abstract: | A confluent endothelial monolayer can be induced to form vascular tubes in response to collagen. We investigated possible mechanisms of collagen-induced tube formation by using antibodies to the VLA-2 integrin receptor and protein kinase C inhibitors. Pre-incubation of cells with anti-VLA-2 (which recognises both the α2 and β1 chains) and AK7 (which recognises only the α2 chain) showed a dose-dependent inhibition of tube formation. At 50 μg/ml, anti-VLA-2 completely inhibited collagen-induced tube formation, whereas AK7 caused only partial inhibition. Both chlorpromazine and trifluoperazine, at concentrations of 10μM, prevented tube formation (> 40% inhibition), In summary, the VLA-2 integrin receptor plays a role in the induction of tube formation by type I collagen. Protein kinase C may be activated during this process. |
