PC12 cells stimulate vascular smooth muscle growth

Sympathetic nerves stimulate vascular growth. The mechanisms underlying this stimulation have not been fully elucidated. PC12 cells and cultures of vascular smooth muscle were used to study sympathetic stimulation of vascular smooth muscle growth. Media conditioned by undifferentiated and differentiated PC12 cells stimulated the growth of vascular smooth muscle (446 +/- 47%). Differentiated PC12 cells produced more growth-stimulatory activity (61.5 +/- 9.6 per 10(6) cells) than undifferentiated PC12 cells (28.5 +/- 8.8 per 10(6) cells). PC12 stimulation of vascular smooth muscle growth was not inhibited by adrenergic receptor antagonists but was reduced by an endothelin antagonist, suramin, and an antibody that neutralized the activity of platelet-derived growth factor. These data suggest that endothelin and platelet-derived growth factor, but not catecholamines, play a role in sympathetic stimulation of vascular smooth muscle growth.