Cellular mechanisms against ischemia reperfusion injury induced by the use of anesthetic pharmacological agents.

Ischemia-reperfusion (IR) cycle in the myocardium is associated with activation of an injurious cascade, thus leading to new myocardial challenges, which account for up to 50% of infarct size. Some evidence implicates reactive oxygen species (ROS) as a probable cause of myocardial injury in prooxidant clinical settings. Damage occurs during both ischemia and post-ischemic reperfusion in animal and human models. The mechanisms that contribute to this damage include the increase in cellular calcium (Ca(2+)) concentration and induction of ROS sources during reperfusion. Pharmacological preconditioning, which includes pharmacological strategies that counteract the ROS burst and Ca(2+) overload followed to IR cycle in the myocardium, could be effective in limiting injury. Currently widespread evidence supports the use of anesthetics agents as an important cardioprotective strategy that act at various levels such as metabotropic receptors, ion channels or mitochondrial level. Their administration before a prolonged ischemic episode is known as anesthetic preconditioning, whereas when given at the very onset of reperfusion, is termed anesthetic postconditioning. Both types of anesthetic conditioning reduce, albeit not to the same degree, the extent of myocardial injury. This review focuses on cellular and pathophysiological concepts on the myocardial damage induced by IR and how anesthetic pharmacological agents commonly used could attenuate the functional and structural effects induced by oxidative stress in cardiac tissue.

Quantitative electroencephalographic studies of the effects of ethanol in rabbits= I. Interaction between ethanol and reserpine.

At a dose of 1 g/kg i.v. ethanol induced in the cortical EEG of rabbits a synchronization which lasted 2-3 hours. Thereafter a pronounced hyper-stimulation occurred which persisted up to 4 hours. Pre-treatment of the animals with reserpine reduced markedly the initial synchronization and abolished the delayed stimulant effect. These findings are discussed in terms of possible interaction between acetaldehyde and biogenic amines.