This study examined the potential of using the pigment lipofuscin, a non‑metabolizable end product of cellular metabolism, as a biomarker of intracellular lipid peroxidation. The study used three‑month‑old male Wistar rats under oxygen pressure of 5 ATA. Confocal microscopy was used to detect lipofuscin in the brain, utilizing the pigment’s autofluorescence. Morphometric analysis of sections from various hippocampal regions revealed lipofuscin accumulation in the rat brain following a single exposure to oxygen at 5 ATA. Lipofuscin inclusions were localized intracellularly, and the pigment distribution across different hippocampal regions was heterogeneous. For the first time, it has been demonstrated that neurons in the CA3 region of the hippocampus exhibit greater vulnerability to the effects of extremely high oxygen pressure and demonstrated more intense lipofuscin accumulation compared to the CA1 region. The dynamics of neuronal lipofuscin accumulation can be considered a promising biomarker of lipid peroxidation intensity and an objective criterion for assessing the degree of oxidative stress in the central nervous system. The obtained data have practical implications for the development of methods to optimize underwater diving regimens with high‑pressure compressed oxygen in animal models.
Alekseeva et al. (Wed,) studied this question.