5-5--6-6--tetrachloro-1-1--3-3--tetraethylbenzimidazolocarbocyanine and 6-hydroxy-2-5-7-8-tetramethylchroman-2-carboxylic-acid

The early antecedents of cerebral palsy (CP) are unknown but are suspected to be due to hypoxia-ischemia (H-I). In our rabbit model of CP, the MRI biomarker, apparent diffusion coefficient (ADC) on diffusion-weighted imaging, predicted which fetuses will develop postnatal hypertonia. Surviving H-I fetuses experience reperfusion-reoxygenation but a subpopulation manifested a continued decline of ADC during early reperfusion-reoxygenation, which possibly represented greater brain injury (RepReOx). We hypothesized that oxidative stress in reperfusion-reoxygenation is a critical trigger for postnatal hypertonia. We investigated whether RepReOx predicted postnatal neurobehavior, indicated oxidative stress, and whether targeting antioxidants at RepReOx ameliorated motor deficits, which included testing of a new superoxide dismutase mimic (MnTnHex-2-PyP). Rabbit dams, 79% gestation (E25), were subjected to 40 min uterine ischemia. Fetal brain ADC was followed during H-I, immediate reperfusion-reoxygenation, and 4-72 h after H-I. Endpoints were postnatal neurological outcome at E32, ADC at end of H-I, ADC nadir during H-I and reperfusion-reoxygenation, and area under ADC curve during the first 20 min of reperfusion-reoxygenation. Antioxidants targeting RepReOx were administered before and/or after uterine ischemia. The new MRI-ADC biomarker for RepReOx improved prediction of postnatal hypertonia. Greater superoxide production, mitochondrial injury, and oligodendroglial loss occurred in fetal brains exhibiting RepReOx than in those without. The antioxidants, MnTnHex-2-PyP and Ascorbate and Trolox combination, significantly decreased postnatal motor deficits and extent of RepReOx. The etiological link between early injury and later motor deficits can thus be investigated by MRI, and allows us to distinguish between critical oxidative stress that causes motor deficits and noncritical oxidative stress that does not.

Topics: Age Factors; Animals; Animals, Newborn; Antioxidants; Ascorbic Acid; Benzimidazoles; Blood Flow Velocity; Brain; Brain Mapping; Carbocyanines; Chromans; Diffusion Magnetic Resonance Imaging; Disease Models, Animal; Embryo, Mammalian; Female; Flow Cytometry; Hypoxia-Ischemia, Brain; Ionophores; Laser-Doppler Flowmetry; Membrane Potential, Mitochondrial; Metalloporphyrins; Microvessels; Mitochondria; Movement Disorders; Muscle Hypertonia; O Antigens; Pregnancy; Rabbits; Reperfusion Injury; Superoxides; Time Factors; Valinomycin

Previous literature reports have demonstrated that nucleated trout erythrocytes in condition of oxidative stress are subjected to DNA and membrane damage, and inactivation of glutathione peroxidase. The present study was undertaken to investigate if mitochondrial membrane potential in stressed conditions was also influenced. Density-separated trout erythrocyte fractions, obtained using a discontinuous Percoll gradient, were submitted to stress conditions and the mitochondrial membrane potential was determined by means of cytofluorimetric analysis after incubation of each subfraction with JC-1, a mitochondrial specific fluorescent probe. The results clearly show that the mitochondrial membrane potential decreased significantly in all erythrocyte fractions, also if the oxidative effect on mitochondria is more severe with increased density (age) of the cell. Ebselen was very effective in preventing mitochondrial depolarization in young as well as in old erythrocytes.

Topics: Animals; Antioxidants; Azoles; Benzimidazoles; Carbocyanines; Cellular Senescence; Chromans; Cyclic N-Oxides; Erythrocytes; Flow Cytometry; Fluorescent Dyes; Free Radicals; In Vitro Techniques; Intracellular Membranes; Isoindoles; Membrane Potentials; Microscopy, Confocal; Mitochondria; Molecular Structure; Organoselenium Compounds; Oxidative Stress; Reactive Oxygen Species; Trout