A decrease in noradrenergic activity in Parkinson's disease might play a critical role in long-term motor complications associated with chronic dopaminergic replacement. Using the rat model of parkinsonism with an additional noradrenergic degeneration induced by the N-(-2-chloroethyl)-N-ethyl-2- bromobenzylamine (DSP-4) toxin we evaluated whether the circling motor activity and dose-failure episodes induced by levodopa (l-DOPA) differ between single (6-OHDA) and double (6-OHDA + DSP-4) denervated animals challenged with a single daily dose of l-DOPA. While single-lesioned animals showed a sensitization-desensitization turning response with a significant increase on day 15 and a decrease on day 22, in double-lesioned animals, the turning activity was maximal from day 1 and did not decay on day 22. Double-lesioned rats exhibited significantly higher number of turns on days 15 and 22 and a significantly lower percentage of dose-failure episodes during treatment. Noradrenergic denervation appears to be associated with prolonged long-term dopaminergic sensitization. This type of response appears to be comparable to that in the clinical setting with intermittent l-DOPA administration where no desensitization occurs once the abnormal response is established. © 2009 Springer-Verlag.
CITATION STYLE
Pérez, V., Sosti, V., Rubio, A., Barbanoj, M., Gich, I., Rodríguez-Álvarez, J., & Kulisevsky, J. (2009). Noradrenergic modulation of the motor response induced by long-term levodopa administration in Parkinsonian rats. Journal of Neural Transmission, 116(7), 867–874. https://doi.org/10.1007/s00702-009-0242-9
Mendeley helps you to discover research relevant for your work.