NGF-Tf Conjugate Prevents Degeneration of Substantia Nigra Neurons in a Mouse Model of Parkinson's Disease.

Nerve growth factor(NGF) was purified from Naja naja atra snake venom and conjugated to transferrin(Tf). This conjugate was intravenously injected into a mouse model of Parkinson's disease (PD). Both immunohistochemical staining and pathological detection showed that the NGF-Tf conjugate could prevent the loss of tyrosine hydroxylase-immunoreactive neurons located in substantia nigra and the cell counts of NGF group were 2 330.0+/-260.3, and those of the MPTP group and the control group were 797.0+/-121.4 and 2 381.0+/-158.0, respectively. In addition, electron microscopic examination revealed significant protection against demyelination and vacuolation in subtantia nigra neurons in contrast to the control group. The i.v. injected NGF-Tf conjugate also reversed the neurodegenerative changes such as karyopyknosis, chromatolysis and intracytoplasmic inclusion in diseased neurons.