Figure 4.

Acute in vivo effects of (±)-fenfluramine on dialysate 5-HT levels measured in blood from conscious rats previously treated with chronic administration of (±)-fenfluramine (fen) or fluoxetine (fluox). For chronic treatments, drugs were dissolved in saline (fen) or 50% ethanol/saline (fluox), and administered s.c. via osmotic minipumps for 2 weeks. On day 14, fenfluramine was dissolved in saline and administered i.v. at 0 min. Serial blood samples were withdrawn at 15 min intervals and immediately dialyzed. Data are mean ± SEM for N=9 rats/group. For Baseline effects, 5-HT levels are normalized to % of vehicle control groups. For acute fenfluramine challenge effects, 5-HT data are peak effects measured 15 min postinjection expressed % of preinjection baseline. * = P<0.05 compared to saline-pretreated controls. Figure modified from ⁴⁸.