Comparing acute effect of Preconditioning, Postconditioning, and combined Pre- and Post- conditioning on oxidative stress markers in healthy subjects

INTRODUCTION: In context to the mechanism that potent oxidant radicals are produced within the first few minutes of reflow and play a crucial role in the development of reperfusion injury, the aim of our study was comparative evaluation of preconditioning versus post-conditioning versus combined pre- and post- conditioning on acute level of oxidative stress markers induced by forearm ischemia-reperfusion injury in healthy subjects. METHODS: A parallel group, open label, pilot study was carried out on healthy subjects. 40 healthy subjects were randomized to four different treatments (n=10/per group). Forearm Ischemia Reperfusion injury (IRI) (group I) was produced by inflation of non-dominant forearm cuff at 200mm Hg for 10 min and then reperfusion for 5 min. Pre-conditioning (group II), Post-conditioning (group III) and, both pre- and post- conditioning (group IV) treatments were also applied to subjects after forearm IRI. Various serum markers of oxidative stress were measured after 10, 30 and 60 min of reperfusion. Results were expressed as mean ± standard error mean and considered significant at p?0.05. One-way and Two-way analysis of variance followed by Student-Newman-Keuls test was used. RESULTS: There was found an increase in thiobarbituric acid reactive substances level during oxidative stress at all time periods after IRI, but decrease in levels of nitric oxide, ascorbic acid, reduced glutathione, ?-tocopherol and catalase at 10 min and subsequently further increase in levels at 30 and 60 min of reperfusion. CONCLUSION: No synergistic effect was seen of combined pre- and post- conditioning in comparison to individual treatment.