Table 3

Induction of extracellular quinones

Quinone (absorbance ×103)Quinone (absorbance ×103)
Controls116  ± 5 (100%)118  ± 14 (100%)
L-DOPA238  ± 83-a (205%)ND
NGF115  ± 7 (99%)99  ± 6 (84%)
L-DOPA & NGF216  ± 83-a (186%)ND
LNAC107  ± 5 (92%)ND
L-DOPA & LNAC123  ± 63-d (106%)ND
ApomorphineND176  ± 33-a (149%)
Apomorphine & NGFND149  ± 3b,c (126%)

Five days after plating, cultures were exposed to 50 μmL-DOPA, 500 μm LNAC, 50 ng/ml NGF, or 10 μmapomorphine as indicated for 24 hr. The extracellular media were then assayed for quinone levels. Data are mean ± standard error (n = 6). These measurements were run with two batches of sister cultures; in each case, n = 6 cultures per condition.

  • ↵3-a p < 0.001 versus controls.

  • 3-b p < 0.01 versus controls.

  • 3-c p < 0.001 for cultures treated with apomorphine/NGF versus apomorphine.

  • ↵3-d p < 0.001 for cultures treated with L-DOPA/LNAC versus L-DOPA.