Inhaled nitric oxide in the prevention of ischemic and reperfusion injuries of the heart during operations with cardiopulmonary bypass

Abstract

Currently, much attention is paid to the study  of the role of nitric oxide, as  a universal transmitter, in the development  of various  pathological conditions. NO  causes relaxation of vascular  smooth muscle,  is involved in protection from ischemic and reperfusion injuries, is a neurotransmitter, regulates  programmed cell death  and proliferation, plays an important role in the secretory  and reproductive system.  New data indicate that inhalation of nitric oxide leads to the formation of new compounds that can be transported  as thiol groups associated with protein in the blood, or act indirectly through nitrites and nitrates, the metabolites of which, as  has  been shown, increase over time during exposure  to inhalation NO. This fact explains the extrapulmonary effects  of inhaled nitric oxide. Experimental and clinical studies  have convincingly shown the effectiveness  of inhaled nitric oxide in the prevention and treatment of: ischemic and reperfusion injury to organs  and tissues,  shock,  damage  to the central nervous  system and kidneys. For cardiac surgery, the effect of pharmacological preconditioning of the myocardium, caused  by inhalation of nitric oxide, is of undoubted  interest. How exactly NO has  a protective effect on the heart is currently unknown, but it is possible  that  direct cGMP/PKG-mediated  and  cGMP-independent  effects  on  the  myocardium  with additional relaxation of smooth muscles,  inhibiting effects  on  platelets, anti-apoptotic,  anti-inflammatory and antioxidant effectors. The number of clinical studies on the protective effect on the heart of inhaled nitric oxide is currently extremely limited, although all the work carried out confirms its additional cardioprotective effect. Most of the work is devoted to the supply of gaseous nitric oxide to the oxygenator of the heart-lung machine and does  not consider other possible options for the implementation of its protective mechanism.