Prague Med. Rep. 2022, 123, 225-242

A Response of the Pineal Gland in Sexually Mature Rats under Long-term Exposure to Heavy Metal Salts

Nataliia Hryntsova1, Ingrid Hodorová2, Josef Mikhaylik2, Anatoly Romanyuk3

1Department of Morphology, Medical Institute, Sumy State University, Sumy, Ukraine
2Department of Anatomy, Faculty of Medicine, Pavol Jozef Šafárik University in Košice, Košice, Slovak Republic
3Department of Pathological Anatomy, Medical Institute, Sumy State University, Sumy, Ukraine

Received December 11, 2020
Accepted November 2, 2022

Pollution with heavy metal salts is an important environmental problem today, having an adverse effect on public health. The endocrine system maintains homeostasis in the body. The antioxidant protection (GPX-1) of the pineal gland in mature rats was studied. Animals of the experimental group represented a model of microelementosis, achieved by adding a mixture of heavy metal salts for 90 days to drinking water: zinc (ZnSO4×7H2O) – 5 mg/l, copper (CuSO4×5H2O) – 1 mg/l, iron (FeSO4) – 10 mg/l, manganese (MnSO4×5H2O) – 0.1 mg/l, lead (Pb(NO3)2) – 0.1 mg/l, and chromium (K2Cr2O7) – 0.1 mg/l. Morphological, statistical and immunohistochemical (GPX-1) research methods were used. Long-term (90-days) intake of heavy metal salts mixture in the body of experimental animals brought about development of the general adaptation syndrome, the stage of chronic stress “subcompensation” in the pineal gland. Morphological rearrangements were of nonspecific polymorphic nature as severe hemodynamics disorder in the organ, impairment of vascular wall morphology, development of tissue hypoxia and oxidative stress, accompanied by processes of accelerated apoptosis in part of pinealocytes, by a significant decrease in glutathione peroxidase level in the organ and reactive astrogliosis as a response to the damaging agent’s action. Along with the negative changes in the pineal gland, a compensatory-adaptive processes with signs of functional stress also occurred. A sufficiently high degree of glutathione peroxidase activity in 39% of pinealocytes located perivascularly, active adaptive glial reaction and activation of synthetic processes in some pinealocytes were also observed.


This study was supported by VEGA 1/0173/19, Scholarship of the Government of the Slovak Republic (2020), the research project “Modern views on the morphogenesis of general pathological processes”, state registration No. 0119U100887 (02.2019-02.2024).


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