NOS3 and endothelial dysfunction: Specifically, endothelial dysfunction induced by T1D mainly results in a reduction in NO synthesis (Figure 3); indeed, a study on a mouse model of streptozocin-induced T1D showed eNOS and NO levels synthesized by endothelial cells were significantly reduced in the corpora cavernosa, with evidence of reversion of these alterations after eNOS gene transfer [37].