Fig. 2.
Vascular conductance in response to increasing doses (A and B) and area under the curve (AUC; C) of serotonin alone (CON; open symbols) and during concurrent perfusion of the nitric oxide (NO) synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME; filled symbols) and the selective serotonin reuptake inhibitor paroxetine (PAX; gray symbols), both alone and in combination with l-NAME (PAX + l-NAME; hatched symbols), in healthy adults [HA, n = 12 (8 women); A and C] and in those with major depressive disorder [MDD, n = 12 (8 women); B and C]. At the highest doses of serotonin, the buffering capacity of NO to offset vasoconstriction was blunted in MDD. Acute treatment with PAX potentiated microvascular sensitivity to serotonin in both groups; however, this effect was greater in HA. CVCmax, maximal cutaneous vascular conductance. Data are means ± SE and were analyzed using two-way or three-way repeated-measures ANOVA. *P < 0.05 CON vs. l-NAME; †P < 0.05 CON vs. PAX; ‡P < 0.05 PAX vs. PAX + L-NAME; #P < 0.05 PAX vs. l-NAME.