AUTORADIOGRAPHIC STUDY OF [I-125] EPIDERMAL GROWTH FACTOR-BINDING SITES IN THE MESENCEPHALON OF CONTROL AND PARKINSONIAN BRAINS POSTMORTEM

Epidermal growth factor (EGF) is assumed to act as a neurotrophic fact or on dopaminergic nigrostriatal neurons in cell cultures and animal b rain. This led us to consider its possible role in the pathophysiology of Parkinson's disease. An autoradiographic study of the distribution of EGF-binding sites was performed in the mesencephalon of controls a nd patients with Parkinson's disease, a neurodegenerative disease asso ciated with dramatic damage to the mesostriatal dopaminergic neurons. Scatchard analysis revealed a single type of binding sites with a high affinity constant, in the various mesencephalic dopaminergic areas ex amined. The characteristics and density of [I-125]EGF-binding sites we re similar in controls and parkinsonian patients. This suggests that E GF receptors in the mesencephalon are unaffected in Parkinson's diseas e and may therefore contribute to the increased activity and survival of the remaining dopaminergic neurons.