evaluation-postocclusive-reactive-hyperemia-rat-paw-skin-using-laser

Evaluation of Postocclusive Reactive Hyperemia in Rat Paw Skin Using Laser Speckle Contrast Imaging

Laser Speckle Contrast Imaging (LSCI) is a modern, non-invasive technique for assessing microvascular perfusion in humans and laboratory animals. The ...

Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology

The overactivation of inflammatory pathways and/or a deficiency of neuroplasticity may result in the delayed recovery of neural function in traumatic brain injury (TBI). A promising approach to protecting the brain tissue in TBI is xenon (Xe) treatment. However, xenon's mechanisms of action remain poorly clarified. In this study, the early-onset expression of 91 target genes was investigated in the damaged and in the contralateral brain areas (sensorimotor cortex region) 6 and 24 h after injury in a TBI rat model. The expression of genes involved in inflammation, oxidation, antioxidation, neurogenesis and neuroplasticity, apoptosis, DNA repair, autophagy, and mitophagy was assessed. The animals inhaled a gas mixture containing xenon and oxygen (ϕXe = 70%; ϕO 25-30% 60 min) 15-30 min after TBI. The data showed that, in the contralateral area, xenon treatment induced the expression of stress genes (, , , and ). In the damaged area, a trend towards lower expression of the inflammatory gene  was observed. Thus, our results suggest that xenon exerts a mild stressor effect in healthy brain tissue and has a tendency to decrease the inflammation following damage, which might contribute to reducing the damage and activating the early compensatory processes in the brain post-TBI.

Effect of Xenon Treatment on Gene Expression in Brain Tissue after Traumatic Brain Injury in Rats.

In vivo studies of the therapeutic effects of argon in traumatic brain injury (TBI) are limited, and their results are contradictory. The aim of this study was to evaluate the effect of a three-hour inhalation of argon (70%Ar/30%O) after an open TBI on the severity of the neurological deficit and the degree of brain damage in rats. The experiments were performed on male Wistar rats ( = 35). The TBI was simulated by the dosed open brain contusion injury. The animals were divided into three groups: sham-operated (SO,  = 7); TBI + 70%N2/30%O (TBI,  = 14); TBI + 70%Ar/30%O (TBI + iAr,  = 14). The Neurological status was assessed over a 14-day period (using the limb-placing and cylinder tests). Magnetic resonance imaging (MRI) scans and a histological examination of the brain with an assessment of the volume of the lesions were performed 14 days after the injury. At each of the time points (days 1, 7, and 14), the limb-placing test score was lower in the TBI and TBI + iAr groups than in the SO group, while there were no significant differences between the TBI and TBI + iAr groups. Additionally, no differences were found between these groups in the cylinder test scores (day 13). The volume of brain damage (tissue loss) according to both the MRI and histological findings did not differ between the TBI and TBI + iAr groups. A three-hour inhalation of argon (70%Ar/30%O) after a TBI had no neuroprotective effect.

Three-Hour Argon Inhalation Has No Neuroprotective Effect after Open Traumatic Brain Injury in Rats.

Laser doppler flowmetry (LDF) allows non-invasive assessment of microvascular functions. The combination of LDF with an occlusion functional test enables study of post-occlusive reactive hyperemia (PORH), providing additional information about vasomotor function, capillary blood flow reserve, and the overall reactivity of the microvascular system.

Article	Year
Effect of Xenon Treatment on Gene Expression in Brain Tissue after Traumatic Brain Injury in Rats. Brain sciences\| PubMed ID: 34356124	2021
Three-Hour Argon Inhalation Has No Neuroprotective Effect after Open Traumatic Brain Injury in Rats. Brain sciences\| PubMed ID: 35884727	2022
Post-occlusive reactive hyperemia variables can be used to diagnose vascular dysfunction in hemorrhagic shock. Microvascular research\| PubMed ID: 38092223	2024

Konstantin Lapin

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