Nerve growth factor control of neuronal expression of angiogenetic and vasoactive factors

In postnatal tissues, angiogenesis occurs in nontumoral conditions on appro priate stimuli. in the nervous tissue, hypoxia, neural graft, increased neu ral function, and synaptic activity are associated with neoangiogenesis, We have investigated the occurrence of neoangiogenesis in the superior cervic al ganglia (scg) of newborn rats treated for 8-21 days with ti-hydroxy-dopa mine (6-OHDA), nerve growth factor (NGF), or 6-OHDA + NGF, The two latter t reatments induced a significant increase in scg size, However, the increase after combined treatment far exceeded that of NGF alone. Similarly , histo logical and histochemical analysis revealed neuronal hypertrophy and endoth elial cell hyperplasia associated with stromal hypertrophy las described by laminin immunostaining) and increased vascular bed las revealed by platele t/endothelial cell adhesion molecule-1 immunostaining) in 6-OHDA + NGF-trea ted pups, NGF, either alone or associated with 6-OHDA, also induced a signi ficant up-regulation of NADPH diaphorase, neuronal nitric oxide synthase, a nd vascular endothelial growth factor expression in scg neurons. The presen t investigation suggests that the increase of scg size induced by NGF and 6 -OHDA + NGF is associated with neoangiogenesis, and that the induction of v asoactive and angiogenic factors in neurons represents a further and previo usly undisclosed effect of NGF.