Figure 4.

Relaxation, hyperpolarization, and NO release caused by SIN-1 in rings of carotid artery. (a) Relaxation and hyperpolarization to SIN-1 in arteries contracted to phenylephrine. The values shown are the maximal and stable relaxation attained 4 min after adding each concentration of SIN-1. (b) Correlation between the NO concentration measured with a porphyrinic sensor 4 min after adding SIN-1 to physiological buffer and the relaxation (○) and hyperpolarization (•) caused by each concentration.