The sensitivity, but not maximum relaxation response was significantly impaired by the presence of either a NO• scavenger (HXC with KCa blockers) or a HNO scavenger (L-cysteine with KCa blockers) in carotid arteries from both sham and diabetic rats (Figures 6A,B, Table 1), which demonstrated that both NO• and HNO contribute to relaxant responses to SNP and diabetes did not impair the responses to either of these mediators when released from SNP rather than the endothelium. This evidence concerns the gene CSN3 and diabetes mellitus.