Table 1.
Effects of unilateral 6-hydroxydopamine (6-OHDA) lesions and treatment with selective 5-HT reuptake inhibitors citalopram and paroxetine on concentrations of dopamine (DA), 3,4-Dihydroxyphenylacetic acid (DOPAC), DA turnover, serotonin (5-HT), 5-Hydroxyindoleacetic acid (5-HIAA), and 5-HT turnover in the striatum of L-DOPA primed rats (n=7/group). Rats were treated with vehicle, citalopram (3 or 5 mg/kg, s.c.), or paroxetine (0.5 or 1.25 mg/kg, s.c.) 30 minutes prior to L-DOPA (6 mg/kg, s.c.) + benserazide (15 mg/kg, s.c.) consistently for 21 days. Before being sacrificed, rats received their respective treatments and were killed 60 minutes after L-DOPA.
| Treatment with L-DOPA 6 mg/kg | DA | DOPAC | DA Turnover | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||||||
| Intact | Lesion | % Intact | Intact | Lesion | % Intact | Intact | Lesion | % Intact | |||||
|
| |||||||||||||
| Vehicle | 12149 ± 495 |
*
|
86 ± 18 | 0.6 ± 0.1 | 2958 ± 217 |
*
|
281 ± 86 | 9 ± 3 | 0.24 ± 0.01 |
*
|
3.87 ± 1.03 | 1620 ± 391 | |
| Citalopram 3 mg/kg | 11449 ± 494 | 177 ± 20 |
^
|
2 ± 0.2 | 3409 ± 428 | 949 ± 431 | 30 ± 15 | 0.30 ± 0.03 | 4.37 ± 1.67 | 1482 ± 601 | |||
| Citalopram 5 mg/kg | 12410 ± 739 | 161 ± 28 | 1 ± 0.2 | 3025 ± 240 | 287 ± 101 | 10 ± 5 | 0.25 ± 0.03 | 1.68 ± 0.47 | 680 ± 190 | ||||
| Paroxetine 0.5 mg/kg | 12418 ± 1416 | 162 ± 14 | 1 ± 0.1 | 3226 ± 267 | 499 ± 338 | 7 ± 2 | 0.25 ± 0.01 | 1.24 ± 0.27 | 392 ± 68 | ||||
| Paroxetine 1.25 mg/kg | 11555 ± 1184 | 151 ± 28 | 1 ± 0.2 | 2853 ± 317 | 173 ± 29 | 7 ± 1 | 0.25 ± 0.02 | 1.66 ± 0.61 | 655 ± 227 | ||||
| Treatment with L-DOPA 6 mg/kg | 5-HT | 5-HIAA | 5-HT Turnover | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||||
| Intact | Lesion | % Intact | Intact | Lesion | % Intact | Intact | Lesion | % Intact | ||||
|
| ||||||||||||
| Vehicle | 278 ± 28 |
*
|
284 ± 67 | 103 ± 18 | 423 ± 37 |
*
|
582 ± 34 | 143 ± 14 | 1.55 ± 0.07 |
*
|
2.52 ± 0.42 | 168 ± 32 |
| Citalopram 3 mg/kg | 371 ± 28 | 271 ± 29 | 75 ± 10 | 407 ± 38 | 633 ± 30 | 160 ± 11 | 1.12 ± 0.11 | 2.55 ± 0.39 | 228 ± 25 | |||
| Citalopram 5 mg/kg | 366 ± 30 | 285 ± 51 | 81 ± 12 | 375 ± 21 | 562 ± 32 | 158 ± 15 | 0.99 ± 0.05 | 2.21 ± 0.30 | 209 ± 26 | |||
| Paroxetine 0.5 mg/kg | 392 ± 45 | 280 ± 21 | 76 ± 10 | 414 ± 26 | 582 ± 15 | 143 ± 8 | 1.12 ± 0.11 | 2.14 ± 0.15 | 198 ± 15 | |||
| Paroxetine 1.25 mg/kg | 432 ± 35 | 286 ± 34 | 69 ± 9 | 420 ± 17 | 565 ± 47 | 135 ± 10 | 1.00 ± 0.08 | 2.08 ± 0.19 | 216 ± 28 | |||
Values (as means ± standard mean error; S.E.M.) are expressed as picograms monoamine or metabolite per milligram wet weight tissue, percent intact vs. intact hemisphere, and turnover estimates were determined by dividing individual subject’s metabolite by monoamine. Differences between lesion (intact vs lesioned striatum), treatments, and lesion x treatment (2 × 5) interactions were determined by 1 and 2-way ANOVAs. Individual cell differences were analyzed with Fisher LSD post-hocs.
p < 0.05 vs. Intact,
p < 0.05 vs. Vehicle.