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

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.

Post-occlusive reactive hyperemia variables can be used to diagnose vascular dysfunction in hemorrhagic shock.

The noble gas argon is one of the most promising neuroprotective agents for hypoxic-reperfusion injuries of the brain. However, its effect on traumatic injuries has been insufficiently studied. The aim of this study was to analyze the effect of the triple inhalation of the argon-oxygen mixture Ar 70%/O 30% on physical and neurological recovery and the degree of brain damage after traumatic brain injury and to investigate the possible molecular mechanisms of the neuroprotective effect. The experiments were performed in male Wistar rats. A controlled brain injury model was used to investigate the effects of argon treatment and the underlying molecular mechanisms. The results of the study showed that animals with craniocerebral injuries that were treated with argon inhalation exhibited better physical recovery rates, better neurological status, and less brain damage. Argon treatment significantly reduced the expression of the proinflammatory markers TNFα and CD68 caused by TBI, increased the expression of phosphorylated protein kinase B (pAKT), and promoted the expression of the transcription factor Nrf2 in intact animals. Treatment with an argon-oxygen breathing mixture after traumatic brain injury has a neuroprotective effect by suppressing the inflammatory response and activating the antioxidant and anti-ischemic system.

Article	Year
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
Positive Effects of Argon Inhalation After Traumatic Brain Injury in Rats. International journal of molecular sciences\| PubMed ID: 39684384	2024

Sergey Kalabushev

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