a, Measurement of cGMP accumulation following phenylephrine stimulation in thoracodorsal arteries pretreated with Scr X or Hb α X peptide in the presence or absence of L-NAME (n=3). b, Dose response to phenylephrine on arteries treated with Scr X or Hb α X in the presence or absence of L-NAME. c, Cumulative dose response curve on thoracodorsal arteries from eNOS−/− mice with Scr X or Hb α X. In b and c, n indicates the number of arteries; value in parentheses shows the number of mice. In b and c, * indicates significance between Scr X vs. Hb α X, ^ indicates significance between Hb α X vs. Hb α X + L-NAME analyzed using 1-way ANOVA. All error bars represent s.e.m.