Morphofunctional changes in the animal organisms under oral exposure to anatoxin-a in subchronic experimental settings

Introduction. Anatoxin-a (2-acetyl-9-azabicyclo[4.2.1]non-2-ene) produced by blue-green algae of the genera Dolichospermum (Anabaena), Aphanizomenon, Cylindrospermum, Oscillatoria, Planktothrix and Raphidiopsis, which are widely spread in the reservoir waters, including those serving as drinking water supply sources for the population. At the same time, the lack of information on the toxic effect of low doses of anatoxin-a (ATX-a) on the morphofunctional condition of warm-blooded animals’ internal organs under prolonged oral intake into the body remains poorly researched. The aim of the research was to study morphofunctional changes in internal organs under the influence of anatoxin-a on the white rat bodies at intragastric intake in subchronic pilot experiments. Material and methods. ATX-a as a certified reference sample in 1% acetic acid solution was dosed daily to male white rats in doses of 0.01; 0.1 and 1.0 µg/kg for 90 days. Morphofunctional changes in 13 internal organs were assessed: thyroid gland, thymus, heart, lung, stomach, liver, spleen, pancreas, ileum, colon, kidney, adrenal glands, testes. Results. It was established that administration of ATX-a in the animals’ body at a dose of 1.0 µg/kg b.w. was followed by significant changes in the same organs compared to the control: testes (2.7-fold increase in the number of spermatogenic cells in some seminal tubules), thymus (4-fold increase in the proportion of lipomatous areas), stomach (3.5-fold increase in hypersecretion of intrinsic glands, 4-fold – disturbance of borders between mucosa and submucosa, 2.7 times – thinning of connective tissue fibres), colon (hypersecretion and 2.4 times increase of blood vessels), pancreas (2.3 times increase of Langerhans islets fibrosis). When exposed to ATX-a at doses of 0.1 and 1.0 µg/kg b.w. in the adrenal glands, an increase in ectopy by 3.3 and 2.5 times, respectively, compared to the control was observed. Limitations. The study is limited by the intragastric intake conditions and the use of one species and sex of warm-blooded animals in the experiment. Conclusion. Morphofunctional changes were revealed in the testes, thymus, stomach, colon, pancreas, adrenal glands of white rats under oral exposure to ATX-a in a subchronic experiment.