Nitric oxide: an important bioregulator.

This limited discussion focuses on the apparent magnitude of the importance of NO-related mechanisms in the maintenance of blood flow to a number of tissue beds, the exaggerated effects in cirrhotics, its effects on platelets and immune modulation, and the potential for manipulation with agonists and antagonists. The possibility of pharmacologic control of this system may play a significant role in the management of patients with liver disease, whether for the treatment of the hypotension associated with low SVR, or endotoxemia/sepsis, or the pulmonary hypertension seen in approximately 1.6% of liver transplant candidates. This is a complex, heavily interrelated system, and the veracity of these various experimental claims for NO needs to be thoroughly evaluated for clinical relevance.