Changes in reactive oxygen species (ROS) production in rat brain during global perinatal asphyxia: an ESR study

A large body of evidence suggests that the production of reactive oxygen sp ecies (ROS) can play an important role in ischemic neuronal injury. However any studies has been performed in hypoxic conditions. In the present exper iments we studied using electron spin resonance (ESR) techniques the ROS re lease in neostriatum of newborn rats subjected to acute perinatal asphyxia (PA) followed by various periods of reoxygenation. Pregnant rats' uteri sti ll containing foetuses were taken out and subjected to PA by immersion in a 37 degreesC water bath during the following periods of time: 5, 10, 15, 19 and 20 min. After performing PA, animals were recovered and ROS measured a fter 0, 5, 15, 30 or 60 min of reoxygenation. Then, pups were sacrificed, t heir neostriatum removed and homogenised with N-tert-butyl-alpha -phenylnit rone (PBN) and diethylenetriamine-pentacetic acid (DPTA) in phosphate-buffe red saline (PBS) and the formed complexes were extracted with ethyl acetate an analysed using an X-band ESR spectrometer. A significant release of ROS was detected at 19 and 20 min of PA after 5 min of reoxygenation. These da ta provide strong evidence that ROS could be involved in neuronal damage du ring PA. (C) 2001 Published by Elsevier Science BY.