Figure 5.

Rate constants after treatments with different doses of carbidopa (A and C) or different enzymatic inhibitors (B and D). Time–activity curves and plasma–input curves were fitted in a two-tissue compartment model (2TCM), rendering K_acc and k₃. Data are depicted as mean±s.e.m. (A) Carbidopa does not influence K_acc. (B) There is no significant effect of inhibition of tryptophan hydroxylase (TPH) by para-chlorophenylalanine (PCPA), aromatic amino acid decarboxylase (AADC) by NSD 1015, or Trp depletion on K_acc, although a trend towards a decrease is seen after PCPA treatment. (C) Carbidopa does not influence k₃. (D) Only PCPA decreases k₃ significantly. *P<0.05.