Experimental research of morphofunctional changes in animal internal organs upon oral ingestion of cylindrospermopsin in chronic exposure terms

Introduction. Cylindrospermopsin (CSP) is a toxin produced by a variety of cyanobacteria species in aquatic areas, increased multiplication associated with climatic changes on the planet. A series of foreign studies indicate the possibility of CSP ingestion into the human organism both with drinking water and recreational use of lake and river water. Along with the general toxic properties of CSP revealed in experiments, the effects of its low doses on morphofunctional state of internal organs of warm-blooded animals under conditions of long-term oral intake remain poorly studied. The aim of the study is to investigate the peculiarities of morphofunctional changes of internal organs of animals under the influence of CSP on the body of white rats at intragastric intake under conditions of chronic experiment. Material and methods. The analytical test sample of cylindrospermopsin, manufactured in Spain, CAS 143545-90-8, was used as an experimental target, the internal organs of outbred white male rats. The toxin was injected intragastrically into male white rats at doses of 0.1 µg/kg, 1.0 µg/kg, 10.0 µg/kg daily for 90 days. Morphofunctional changes were explored using morphological, morphometric and stereometric research methods. Results. It was found that CSP only at a dose of 10 mcg/kg under conditions of chronic oral exposure causes the following structural and functional disorders in experimental animals, the severity of which remained in comparison with the control: liver fatty degeneration by 2.1 times, micronecrosis by 80%; kidney necrotic changes in the renal glomeruli by 2 times; stomach and in the large intestine – hypersecretion of its own glands by 3.5–4 times; in the thyroid gland – desquamation of thyrocytes by 5 times; in the testes, there is a pronounced rarefaction of spermatids and spermatozoa in the absence of the control group. Limitations. The study is limited by the conditions of intragastric intake into the body of experimental animals and the use of one species and sex of warm-blooded animals in the experiment. Conclusion. Chronic oral exposure to CSP at a dose of 10 micrograms/kg causes significant morphofunctional changes in the internal organs of experimental animals compared with the control, with the most stimulating effects in the stomach and large intestine and structural and functional abnormalities in the testes and thyroid gland, as well as necrotic disorders in the liver and kidneys.