Study Of Normobaric Hyperoxia Effects During Focal Hypoxia-ischemic Injury In Mice Using Optical Spectroscopy Measurements

Optical spectroscopy has seen tremendous growth and development in recent years and has been extensively used to characterize the optical properties of biological tissues. The purpose of this study is to investigate the values of oxygen saturation and concentration of hemoglobin in mice with focal hypoxic ischemia after being recovered in normobaric hyperoxia. Mice at five different age levels were used for this purpose, in order to see the effects of hyperoxia at different developmental stages of the brain; ischemia was induced in them by ligating their right carotid artery and subjecting them to hypoxic (8% oxygen) environment for half an hour. Mice were then subjected to normobaric hyperoxia (100% oxygen) or room air for half an hour. The hyperoxia group showed an increase in oxyhemoglobin concentration in all age groups of mice, also an increase in oxygen saturation was noted in all age groups of mice, except the P28 group. These results indicate that normobaric hyperoxia increases oxyhemoglobin concentration in adult mice with focal cerebral ischemia and the extent of improvement seem to vary with age. This study continues to show the efficiency of optical spectroscopy in determining tissue optical properties, however one of the drawbacks to this study using needle-like probe was the skin of the animal gave rise to artifacts during measurements and had to be removed to get better optical readings.