TABLE 2

Clozapine enhances the l-DOPA-stimulated DA metabolism in striatum

Twenty-four hours after MPTP treatment (see Table 1), lesioned and intact (saline-treated) mice were administered a single dose of 20 mg/kg i.p. clozapine, 100 mg/kg i.p. l-DOPA, clozapine, and l-DOPA or vehicle and killed 1 h later. DA and metabolites were estimated in striatum as described under Materials and Methods.

Treatment
DA
DOPAC
HVA
DOPAC + HVA/DA
pmol / mg protein ± S.E.M.
Saline 464 ± 15 70 ± 9 50 ± 2 0.25
MPTP 116 ± 16* 23 ± 2* 21 ± 2* 0.38
Control + l-DOPA 544 ± 12** 160 ± 2** 108 ± 5** 0.49
MPTP + l-DOPA 228 ± 12** 145 ± 20** 123 ± 14** 1.17
Saline + clozapine 580 ± 48** 147 ± 9** 78 ± 4** 0.39
MPTP + clozapine 246 ± 21 62 ± 5** 45 ± 5** 0.43
Saline + clozapine + l-DOPA 567 ± 39 432 ± 51*** 172 ± 6*** 1.06
MPTP + clozapine + l-DOPA
279 ± 11
402 ± 60***
243 ± 31***
2.31

  • ↵* p < 0.05 compared with saline-treated animals.

  • ↵** p < 0.05 compared with saline- or MPTP- treated animals, respectively.

  • ↵*** p < 0.05 compared with saline- and MPTP- treated animals not given l-DOPA. n = 6 to 8.