Figure 1.

This figure illustrates the role of nitric oxide synthase (NOS) and nitric oxide in bacteria, humans, and plants in regard to oxidative stress, cellular defense and repair, and other cellular processes. There are 3 isoforms of NOS in humans and more are present in plants. It has recently been discovered that NOS and NO play an important role in cardiovascular health and erectile function. The roles of NOS and NO are diverse and important in bacteria, humans, animals, and plants.