1. Nitric oxide (NO) is a potent vasodilator and cell signaling molecule.

2. Major source of NO in cellular environment is nitric oxide synthase (NOS)

3. NOS activity is regulated at multiple levels, including transcription, post translational and subcellular targeting/translocation.

4. NO signals the target cells either through cGMP dependent or independent pathways.

5. cGMP independent events are mainly protein modifications such as nitration and nitrosylation.