Experimental study of morphological changes in the heart and blood vessels in the course of chronic fluoride intoxication

Introduction. Clinical studies have shown the development of a complex of non-specific changes in internal organs due to chronic fluoride intoxication. The accumulation of fluorine in the body initiates free radical oxidation, promotes the development of pathological processes in the heart against the background of an imbalance between pro- and antioxidants, and vascular endothelial dysfunction. Pathological activation of intima cells leads to unbalanced production of damaging factors, changes in the hemostasis system, and entails morphological and functional disorders of organs.

Materials and methods. The experiments were carried out on one hundred twenty white male rats. A morphological study of the heart, blood vessels was performed out at 1, 3, 6, 9 and 12 weeks of chronic fluoride intoxication.

Results. The 1st-3rd weeks of the experiment are characterized by the preservation of the morphological structure of the cardiac muscle against the background of the previously shown a compensatory activation of the components of the redox-signalling system, which provided a decrease in the intensity of free radical processes. With an increase in the duration of exposure to sodium fluoride (6–9 weeks) these mechanisms failure was noted, which was manifested by the development of degenerative changes in the myocardium, progressing up to the 12th week of the experiment. The described changes correlated with the development of endotheliosis, degenerative and fibroplastic processes, circulatory disorders in the vessels of the heart and other organs.

Limitations. Histological findings are descriptive.

Conclusion. The results obtained are of practical importance for the elaboration of effective methods for timely organ-protective prevention and correction of pathomorphological disorders, depending on the organ-specific features and duration of fluoride intoxication.

Compliance with ethical standards. Experimental studies were carried out in the period 2012-2019. The keeping, feeding and withdrawal animals from the experiment were carried out in accordance with the requirements of the Order of the Ministry of Health and Social Development of Russia of the Russian Federation “On approval of the Rules of Laboratory Practice” (No. 708n of 23.08.2010), of the Order of the Ministry of Health of the Russian Federation “On approval of the Rules of Good Laboratory Practice” (No. 199n of 01.04.2016), as well as the Guide for the Care and Use of Laboratory Animals (1996). Permission to conduct studies was obtained from the Bioethical Committee of the Research Institute for Complex Problems of Hygiene and Occupational Diseases (protocol No. 1 of January 19, 2012, protocol No. 3 of November 26, 2018).

Contribution:
Bugaeva M.S. — concept and design of the study, collection and processing of material, writing a text;
Bondarev O.I. — collection and processing of material;
Yadykina T.K. — collection and processing of material, editing;
Zhukova A.G. — collection and processing of material, statistical processing, editing;
Mikhailova N.N. — concept of the study, editing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: January 25, 2023 / Accepted: March 24, 2023 / Published: May 29, 2023