Effect of glutamatergic inhibition on leptin-induced BP rise in obesity. Male C57BL/6 mice fed on a HFD for 3 months followed the same surgical procedure as described in Fig. 1. After 1-week postsurgery recovery, mice received daily intra–third-ventricle injection of leptin for 2 consecutive days. In the second day, mice received an intra–third-ventricle injection of KYN vs vehicle 30 minutes prior to leptin administration. Curves on the left present the minute-by-minute average levels of (a) systolic, (b) diastolic, and (c) mean BP and (d) heart rate over a 4-hour postinjection period. Bar graphs on the right present average levels of (e) systolic, (f) diastolic, and (g) mean BP and (h) heart rate during early and late phases (35 to 65 minutes and 105 to 165 minutes postinjection) of leptin-induced hypertension in HFD-fed mice. Phase 1 (35 to 65 minutes) is outlined by a gray dotted line (a–d), whereas phase 2 (105 to 165 minutes) is outlined by a red dotted line (a–d). Error bars reflect mean ± standard error of the mean. *P < 0.05, **P < 0.01; n = 5 mice per group. aCSF, artificial cerebrospinal fluid; bpm, beats per minute; DBP, diastolic blood pressure; HR, heart rate; Inj & Rec, injection and recovery; Lep, leptin; MBP, mean blood pressure; n.s., nonsignificant; SBP, systolic blood pressure.