Yonago Acta medica 1997;40:5361
A < 10 Kilodalton Fraction of Cerebrospinal Fluid from Patients with Parkinson’s Disease Decreases the Survival of Rat Mesencephalic Dopaminergic Neurons in Culture
Katsuko Mishima, Takao Takeshima and Kenji Nakashima
Division of Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago 683, Japan
Parkinson’s disease (PD) is characterized by loss of dopaminergic neurons of the pars compacta in the substantia nigra. It has been suggested that environmental or intrinsic toxic factors for mesencephalic dopaminergic neurons are associated with this progressive neuronal loss. Using a primary rat mesencephalic dopaminergic culture method, we tested the impact of the cerebrospinal fluid (CSF) obtained from patients with PD on the survival of mesencephalic dopaminergic neurons. Specimens of CSF were obtained by lumbar puncture from 6 patients with PD (including 2 patients never treated with L-dopa) and control patients with other neurological diseases. On day 4 of in vitro culture of the CSF specimens, 20% of the growth medium was exchanged with the < 10 kDa fraction of CSF. The survival of dopaminergic neurons was evaluated by tyrosine hydroxylase (TH) staining on day 6 of in vitro culture. The percentage of TH-positive neurons significantly decreased in cultures treated with the < 10 kDa fraction of CSF from PD patients (3.0 ± 1.4%; mean ± SD) than in those from control subjects (6.2 ± 2.5%, P < 0.05), without any significant difference to the total cell number. The toxicity of CSF from PD patients not treated with L-dopa was significantly higher than that from PD patients treated with L-dopa. A dose-response curve of 1-methyl-4-phenylpyridinium ion (MPP+) toxicity on this culture was tested in a range from 0.1 to 20 µM (median effective dose, 1.0 µM). The mean effect of the 20% medium replacement with the < 10 kDa fraction of CSF from PD patients was equivalent to that of 5.0 µM MPP+. It is suggested that a somewhat toxic factor exists in CSF of PD patients, which is one of the causes of the development of PD.
Key words: cerebrospinal fluid; mesencephalic dopaminergic neurons; microisland cultures; neurotoxicity; Parkinson’s disease