MORPHO-FUNCTIONAL CHARACTERISTICS OF VERTEBRATE REPRODUCTIVE SYSTEM UNDER CONDITIONS OF THEIR HABITAT EXPOSURE TO HEAVY METAL COMPOUNDS

Abstract

The review presents data of modern Russian and foreign literature on the morpho-functional changes in the vertebrate reproductive system after exposure of their habitat to heavy metal compounds. The data presented in the review indicate the multilateral negative effect of heavy metal compounds on the vertebrate reproductive system. The evidence shows the direct and mediated negative impact of heavy metal compounds on the organism of animals and humans. In vertebrates, a disturbance of the reproductive system morphogenesis is observed, the gonads demonstrate marked destructive changes in the developing germ cells and their resorption. In the ovaries, the rapid depletion of the follicular reserve was noted. In the testes, the amount of connective tissue was increased due to a reduction of the proportion of generative structures, together with the frequent incidence of convoluted seminiferous tubules with a destruction of seminiferous epithelium. In the lumen of the tubules, polynuclear giant cells appeared, while in the tubular wall the increased permeability of blood-testis barrier was observed. Simultaneously, the decrease of fertilizing capacity of male and female gametes was detected. These morphological and functional changes in the reproductive system of animals were observed in association with reproduction activation (reduction of the age of puberty, the increase in the proportion of individuals participating in reproduction). The extent of damage of the reproductive system varies considerably in different species, indicating the presence of species adaptation to the adverse effects of heavy metal compounds.

Keywords

testes / ovaries / reproduction / heavy metals / anthropogenic influence / vertebrates

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