Vasoactive intestinal peptide and nerve growth factor effects on nerve regeneration.

Sixty rat sciatic nerves were used to study the effects of vasoactive intestinal peptide (VIP) and nerve growth factor (NGF) on nerve regeneration. They were divided into three groups. Groups 1 and 2 were treated with VIP and NGF, respectively, after dividing the nerves without repair and placing them in silastic chambers. Group 3 served a control. The rate and quality of nerve regeneration were compared among the groups using caliper measurements and histologic evaluation. Both VIP and NGF groups showed an enhanced rate of regeneration at three weeks as compared to controls (p < 0.05). The quality of nerve regeneration histologically and by axonal counting was not significantly different among the three groups, except for the presence of less vascularity in the VIP as compared with the NGF group. In addition to NGF, VIP appears to increase the rate of nerve regeneration as compared to controls.