TPH1 and Hyperglycemia: Expression levels of SERT, TPH1, and MAOA mRNAs were compared between ACH-3P cells incubated (for 24 or 72 h) in the presence of 25 mM D-glucose (hyperglycemia) and (1) 5.5 mM D-glucose supplemented with 19.5 mM L-glucose (osmotic control; Figure 1) or (2) 5.5 mM D-glucose (control; Figure A1 in Appendix A).