Restoring Spinal Noradrenergic Inhibitory Tone Attenuates Pain Hypersensitivity in a Rat Model of Parkinson’s Disease

Figure 6

Effects of droxidopa and clonidine on thermal and mechanical hypersensitivity in 6-OHDA-lesioned rats. Rats were i.p. injected with 10 mg/kg droxidopa and 20 mg/kg droxidopa or equal volume of saline on the 5th week after surgery. ((a)–(d)) Systemic application of droxidopa significantly inhibited thermal (a) and mechanical hypersensitivity ((b)–(d)) in 6-OHDA-lesioned rats (, , and for 10 mg/kg droxidopa and and for 20 mg/kg droxidopa compared to the saline control, = 5-6 for each group). ((e)–(h)) Systemic application of clonidine (200 µg/kg, i.p.) significantly inhibited thermal (e) and mechanical hypersensitivity ((f)–(h)) in 6-OHDA-lesioned rats (, , and compared to the saline control, = 5-6 for each group).

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