RESUMEN
The "nerve growth factor" is a polipeptide isolated from salivary glands of some mammals. Its main physiological effect is on the autonomic nervous system. The injection of antiserum in newborn animals leads to nearly total destruction of the sympathetic ganglia (immunosympathectomy). Anti-nerve growth factor labelled with Iodine-131 was injected in rats for the determination of organ distribution at different times (2,4,6,8 and 24 hours). A selective concentration in the adrenal medulla was obtained at 4 hrs. after intravenous administration of 50 uCi of anti-nerve growth factor with an specific activity of 0.001 g/mCi that permits, for the first time, the scan of the adrenal medulla. No intolerance or radiotoxicity was observed in the animals during a six-month follow-up period. The results are very encoragin, and the application of this new method in humans is at present under study.