1,1,3 Tricyano-2-amino-1-propene (
Triap) is a small molecular weight compound which increases the rate of nerve and tissue regeneration in several experimental systems. Early experiments with this compound showed that, like
nerve growth factor (
NGF),
Triap induced neurite formation in chick spinal ganglia. To assess the similarity between
NGF and
Triap, we compared the effects of
Triap and
NGF on a rat pheochromocytoma cell line (PC12) and on cell survival in a primary chick neuronal culture. In the latter,
Triap at less than 0.01 nM preserved neurons and caused them to extend neurites as did 1 nM
NGF.
Triap induced neurite outgrowth in the PC12 cell line giving a maximal response (40-50% of the maximal response of
NGF) at a concentration of 20 micrograms/ml (151 microM).
Triap's morphological effects were not inhibited by
antibodies directed against
NGF or the
NGF receptor. Low concentrations of
Triap also potentiated the morphological effects of
NGF.
Triap induced an increase in cell-substratum adhesion and cellular
hypertrophy in PC12 cells and also potentiated the adhesive actions of
NGF.
Triap had no effect on
ornithine decarboxylase activity even though it potentiated
NGF's effects on this
enzyme. These data indicate that
Triap induces neurotrophic effects and does not seem to act through the same mechanisms as
NGF but can potentiate many of
NGF's morphological and biochemical actions.