Abstract
Exogenous proteins have been introduced into naive and nerve growth factor (NGF)-primed pheochromocytoma cells by pressure microinjection. Microinjection of cells did affect NGF-induced neurite outgrowth by these cells over periods of up to 3 days. Injected NGF failed to elicit neurite outgrowth or regeneration in the absence of extracellular NGF and failed to enhance it in its presence. Injected anti-NGF IgG failed to inhibit neurite outgrowth or regeneration induced by extracellular NGF. Similar results were obtained for both nuclear and cytoplasmic injections.
