Fig. 1: Dopamine-stimulated PLM in D4R-expressing CHO cells.
From: Methylation-related metabolic effects of D4 dopamine receptor expression and activation
a The dopamine-stimulated D4R-mediated PLM cycle (lower left) functions in parallel to the canonical methionine cycle (lower right) and is completely dependent on MS activity and 5-methyltetrahydrofolate (methylTHF). Transsulfuration of homocysteine to cystathionine and cysteine supports GSH synthesis. b D4.4R-expressing CHO cells were treated with dopamine (DA) for 30 min with or without pretreatment with the highly D4R-selective antagonist L-745870 or the moderately selective D4R antagonist clozapine. Data are mean ± SEM of two experiments (n = 6). *p < 0.05 vs. Control. c Non-transfected CHO cells (WT) and CHO cells expressing D4.2R, D4.4R, and D4.7R were treated with graded concentrations of dopamine. Data are average (±SEM) of two experiments (n = 6). (c) (p < 0.05). d CHO cells expressing D4.2R, D4.4R, or D4.7R were treated with dopamine (10 µM; 30 min) or dopamine + the PI3 kinase inhibitor wortmannin (100 nM; 60 min). A Western blot was probed with anti-phospho-MAP kinase (upper panel) or anti-MAP kinase antibodies (lower panel)
