Introduction A still and bloodless operative field provides the surgeon with optimal conditions to perform delicate coronary anastomosis, while effective myocardial protection avoids myocardial injury during this process.1 Cold crystalloid cardioplegia has been the cornerstone of this strategy by inducing electromechanical arrest and further reducing oxygen demand with hypothermia.2 In spite of...

Maximal exercise in normoxia results in oxidative stress due to an increase in free radical production. However, the effect of a single bout of moderate aerobic exercise performed in either relative or absolute normobaric hypoxia on free radical production and lipid peroxidation remains unknown. To examine this, we randomly matched {according to their normobaric normoxic VO2peak [peak VO2 (oxyg...

The free radical scavenging and/or generating activity of dopamine-4-O-sulfate was examined and compared with that of dopamine. In humans, dopamine mostly exists in two isomeric forms of sulfate ester conjugates as metabolites; i.e., dopamine-3-O-sulfate and dopamine-4-O-sulfate in the circulation. Dopamine is generally believed to be oxidized by molecular oxygen or another reactive oxygen spec...

T HE MOST significant limiting factor in the further expansion of clinical cardiac transplantation consists of the availability of suitable donors and the duration of viability of the organ following harvest. Currently, the safe limits of static cold cardiac preservation are considered to be four to six hours using the standard Stanford preservation solution as listed in Table 1. Belzer and col...

The focus of this review is to provide state-of-the-art knowledge on the involvement of oxygen free radicals (OFR) in carcinogenesis with a particular reference to skin model system as the process of cancer development is best understood in this organ. However, a brief description of the role of OFR in other organs is also provided. The term OFR refers to forms of oxygen exhibiting high reactiv...

Oxygen-derived free radicals and other oxidizing species are thought to be involved in inflammation and ischemic tissue injuries. Recently, oxygen-derived free radicals also have been implicated in tissue injury of the myocardium subjected to ischemia/reperfusion. The purpose of this investigation was to determine if electrolysis of a physiological buffer would serve as a source of free radical...

The protective effects of carvedilol, a new beta-adrenergic receptor blocker and vasodilating antihypertensive agent, against oxygen free radical-mediated injury were studied in cultured bovine endothelial cells and compared with five other beta-blockers. Carvedilol dose-dependently inhibited oxygen radical-induced lipid peroxidation (50% inhibition at 2.6 mumol/L) and glutathione depletion (50...

Oxidative stress is thought to play an important role in the initiation and progression of renal, cardiovascular, neoplastic, and neurodegenerative diseases. It is also widely believed that oxidative stress is a main cause of aging. Although considerable progress has been made in the understanding of the sources and actions of oxidative stress, the true role of oxygen-derived free radicals in t...

Although oxygen has been known to be toxic for more than 200 years, the clinical importance of oxygen toxicity was not appreciated until an epidemic of retrolental fibroplasia occurred in the early 1950s. Oxygen at high partial pressures is toxic to the respiratory, cardiovascular, nervous, and gastrointestinal systems. Toxicity results from the formation of oxygen-free radicals. These arise wi...

The concentrations of ROS were measured in samples of the sensorimotor brain cortex and in the rat blood. We measured the following parameters: The six lines spectra, nitroxide radical, free hydroxyl radical and singleton oxygen. Their concentration was measured under physiological conditions, after the nociceptive stimulation and after the application of melatonin, both in normal and stimulate...