Vascular endothelial growth factor modulates contractile response in microvascular lung pericytes

Background: Pericytes are capillary support cells that may play a role in regulating permeability by their contractile responses. Vascular endothelial growth factor (VEGF) may play a role in the increased permeability found in sepsis and other inflammatory conditions. The purpose of this study was to evaluate the role of VEGF in regulating pericyte contraction. Methods: Rat microvascular lung pericytes were isolated according to previously described methods and cultured on collagen gel matrices. Cells were exposed to VEGF (10, 100, and 1000 pg/mL) for varying time periods (0, 10, 30, 60, and 120 minutes). The gels were released and their contractile responses digitally quantified. Results: At all doses, VEGF induced initial pericyte relaxation (contraction 85% to 90% of controls;, P < .001). This was followed-up by increased and sustained contraction (107% to 120% of controls; P < .01). Conclusions: VEGF modifies the contractile response of microvascular lung pericytes. This mechanism may play a role in the increased permeability demonstrated in inflammatory states. (c) 2006 Excerpta Medica Inc. All rights reserved.