Figure 8.

Increase in $k_1$ leads to a poorer homeostatic regulation of DOPA due to TH inhibition by increased Tyr levels. The graph shows DOPA and DA concentrations when $k_1$ = 100 $\mathsf{\mu }$M/min. Other rate constant values as in Figure 6c. Initial concentrations: Tyr = $3.7\times {10}^3 \mathsf{\mu }$M, DOPA = 51.2 $\mathsf{\mu }$M, DA = 18.1 $\mathsf{\mu }$M, $D{A}_{ves}$ = 228.9 $\mathsf{\mu }$M, $D{A}_{ex}$ = 1.6 $\mathsf{\mu }$M.