Fig. 2.
Comparative concentration–response curves for NO or nitrosoglutathione (GSNO) for the stimulation of GC activity and for eliciting downstream effects. (A) Clamped NO concentrations were delivered to intact rat platelets maintained in vitro (filled squares) or to purified bovine lung GC incubated with presumed physiological concentrations of GTP and ATP (circles); the resulting GC activity is expressed as a fraction of maximum (left-hand ordinate). The concentration–response curve for cGMP-dependent phosphorylation of vasodilator-activated phosphoprotein (VASP) after exposing rat platelets to NO for 1 min is also expressed as a fraction of the maximum level achieved (open squares and right-hand ordinate). Data are from Roy et al. [47] and Mo et al. [48]. (B) Comparative potency of S-nitrosoglutathione for elevating cGMP (1 min exposure) and eliciting relaxation of rat aorta in vitro; from Mullershausen et al. [54] with permission.