Retinal neurotoxicity induced by inhalation of isopropyl nitrite

Abstract

Purpose: Popper is a slang term given broadly to drugs of the chemical class called alkyl nitrites that are inhaled. Most widely sold products include the original isopropyl nitrite (IPN) a mix of isopropyl alcohol with nitrous acid and sulphuric acid. Multiple cases of retinopathy have been reported since 2001 that have been associated with the inhalation of poppers, predominantly in Europe. However, no clear information about the effect of these inhalant agents on retinal cells have been shown to date. Our work tries to address the neurotoxic effect of IPN on outer retinal cells evidenced by immunocytochemical technique on murine model.Methods: 8 Opn4‐KO mice were used, n:4 were treated with IPN using a aero chamber inhalator for 20 days (1 mL/5 s) and n:4 with oxygen (ctrl group). CARR antibody was used, encoded by the Arr3 gene in murine species. All the animals were supplied by the Animal Experimentation Center of the UAH. The euthanasia of the animals was carried out in accordance with RD 53/2013 Spanish regulations.Results: The sagittal sections of the Opn4 mouse retina taken with confocal microscopy at 40×, the expression of arrestin‐C can be observed, predominantly in the internal and external segments of the cones without disruption, the presence of CARR confirms the presence of cells of retinal cone in our CARR cuts (Cy5, red), The exposure parameters of the samples and image capture in the confocal microscope were taken based on the immunoreactivity in the Opn4 animal model, remaining stable for the rest of the photos. Labelling at the level of the outer plexiform layer is equally intense in Opn4 Ctrl and Opn4 to animals.Conclusions: The results failed to demonstrate morphological changes of clinical importance that could determine a neurotoxic role in the retina of IPN inhalation; however, we propose the existence of other factors and/or pharmacological interactions with the use of poppers in the aetiopathogenesis of this new ophthalmological disease.