Figure 1.

Production of ${{\text{O}}_2}^{\underset{\_}{•}}$ by 100 μM 5-HT. Levels of ${{\text{O}}_2}^{\underset{\_}{•}}$ were measured by EPR spectrometry in basal conditions (white column) or in the presence of 5-HT (black column) in rat IPA (A) or aorta (B). (C) 5-HT increases ONOO⁻ levels in rat IPA. (D) 5-HT does not modify SOD activity measured in rat IPA. Data are expressed as mean ± SEM. ^** and ^* mean a significant difference for P < 0.01 and P < 0.05 respectively. n is the number of rats.