HISTOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL ASPECTS OF THE INVOLVEMENT OF OXIDATIVE STRESS IN THE PATHOGENESIS OF THE TOXICITY OF NEUROTOXIC ORGANOPHOSPHORUS COMPOUNDS

Abstract

[...]animals were euthanized, liver and kidney were collected for immunostaining examinations. The evaluation of the response of the main organs of excretion (kidney) of the evaluated compounds was followed. Keywords: galantamine, neurotoxic organophosphorus compound, antidote, oxidative stress Funding: The project was financed by the Ministry of Defense from the budget allocated to the Sectoral Research and Development Program.

The objective is to highlight the immunostaining aspects of oxidative aggression involved in the pathogenesis of organophosphates toxicity.

Material and methods. The in vivo studies were carried out with the approval of the Ethics Commission of INCDMM Cantacuzino and The Directorate for Veterinary Health and Food Safety no. 38/25.08.2023. Six batches of 5 Wistar rats were used. Galantamine from natural extracts and the one obtained by chemichal synthesis, and an organophosphorus compound were administered daily, for 7 days. Finally, animals were euthanized, liver and kidney were collected for immunostaining examinations. Hematoxylin-eosin-stained slides were run and antibodies specific for inflammation and oxidative stress (CD8, CD 45, iNOS) were applied.

Results and discussion. The evaluation of the response of the main organs of excretion (kidney) of the evaluated compounds was followed. Administration of the toxicant (median lethal dose) induced in the renal interstittum mononuclear inflammatory infiltrate. Glomeruli show variable degrees of vacuolar dystrophy and edema. At the level of the liver, the cellular architecture is preserved, but hepatic steatosis appears diffusely microvesicular. Administration of the antidote significantly improved the kidney damage. Focally, glomeruli are observed with rare intraglomerular inflammatory infiltrates, without hyalinization or dystrophy, with viable cells. Interstitial rare mononucleated inflammatory elements are noted. The hepatocytic architecture is preserved, without observing pathological elements. The histopathological changes were correlated with the immunostaining evidence of inflammation through the expression of CD 45 and CD 8 antibodies and the involvement of oxidative stress through the expression of iNOS at the renal level in case of toxic exposure.

Conclusions. Oxidative stress and irreversible inhibition of cholinesterase are important pathogenic mechanisms of toxicity of neurotoxic organophore compounds. Administration of antidote treatment alleviates liver and kidney toxicity. Galantamine, through its reversible anticholinesterase and antioxidant effect, can be a therapeutic alternative.

Keywords: galantamine, neurotoxic organophosphorus compound, antidote, oxidative stress

Funding: The project was financed by the Ministry of Defense from the budget allocated to the Sectoral Research and Development Program.

Obiectivul constd in evidentierea aspectelor histopatologice si imunohistochimice ale implicarii agresiunii oxidative in patogenia toxicitatii organofosforicelor neurotoxici.

Material si metode. Studiile in vivo s-su desfasurat cu avizul Comisiei de Eticá din INCDMM Cantacuzino si a Directiei Sanitar Veterinare si Pentru Siguranta Alimentelor (DSVSA) nr 38/25.08.2023. Au fost utilizate sase loturi de cate 5 sobolani Wistar la care s-a administrat zilnic timp de 7 zile prin gavare galantamina obtinutá din extracte naturale si respectiv prin sintezá chimica $1, dupd 30 minute, un insecticid organofosforic, neurotoxic. Au fost urmarite semnele de intoxicatie si mortalitatea. La sfársitul experimentului, animalele au fost eutanasiate si s-au recoltat probe din rinichi pentru examinári imunohistopatologice. Au fost executate lame colorate cu hematoxilinaeoziná si s-au aplicat anticorpi specifici inflamatiei si stresului oxidativ (CD8, CD 45, iNOS).

Rezultate si discutii. S-a urmarit evaluarea raspunsului principalelor organe de metabolizare si excretie a compusilor evaluati, respectiv ficat si rinichi. Administrarea toxicului (doza letala mediana) a indus in interstitiul renal infiltrat inflamator mononuclear. Glomerulii prezintá grade variabile de distrofie vacuolará si edem. La nivel hepatic se pastreaza arhitectura celulara insá difuz apare steatoza hepatica. microveziculará. Administrarea antidotului a ameliorat semnificativ leziunile renale. Focal se observa glomeruli cu rare infiltrate inflamatorii intraglomerulare, fara hialinizare sau distrofie, cu celule viabile. Interstitial se remarca rare elemente inflamatorii mononucleate. Arhitectura hepatocitara este pastrata, fara a se observa elemente patologice. Modificarile histopatologice s-au corelat cu evidentierea imunostaining a inflamatiei prin expresia anticorpilor CD 45 si CD 8 si a implicarii stresului oxidativ prin expresia iNOS la nivel renal in cazul expunerii la toxic.

Concluzii. Stresul oxidativ si inhibitia ireversibilá a colinesterazei reprezintá mecanisme patogenice importante ale toxicitatii compusilor organofosorici neurotoxici. Administrarea tratamentului antidotic amelioreazá toxicitatea hepaticá si renalá. Galantamina prin efectul anticolinesterazic reversibil si antioxidant poate constitui o alternativá terapeutica.

Cuvinte-cheie: galantaminá, compus organofosforic neurotoxic, antidot, stres oxidative

Finantare: Proiectul a fost finantat de Ministerul Apárárii din bugetul alocat Programului Sectorial de Cercetare Dezvoltare

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*Corresponding author: Cristina Anca Secará, e-mail: [email protected]