Polyneuropathy is observed in treated patients with Parkinson disease. Peripheral axonal degeneration is related to nerve growth factor metabolism. The causes for this axonal degeneration and the role of levodopa itself are not known. Levodopa may experimentally exert supportive effects on nerve growth factor synthesis and on growth hormone production, a hormonal compound with regenerative potential.
The objective of this study was to investigate the effects of soluble 250-mg levodopa/benserazide administration on plasma occurrence of levodopa, nerve growth factor, and growth hormone in patients with Parkinson disease over an interval of 60 minutes.
Levodopa moderately increased bioavailability of nerve growth factor and growth hormone combined with the rise of levodopa. Nerve growth factor data and levodopa values correlated to each other.
Axonal degeneration may not be due to levodopa itself, as levodopa supports production of nerve growth factor and of growth hormone. Both may complement each other for neuronal survival.
*Department of Neurology, St Joseph Hospital Berlin-Weissensee, Berlin, Germany; †Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany; and ‡Department of Psychiatry, Campus Benjamin Franklin, Charite-University Medicine, Berlin, Germany.
Address correspondence and reprint requests to Thomas Müller, MD, Department of Neurology, St Joseph Hospital Berlin-Weissensee, Gartenstr. 1, 13088 Berlin, Germany; E-mail: email@example.com; firstname.lastname@example.org
The authors have nothing to disclose.