Morphological effects of bacterial compounds on the testes of Eupemphix nattereri (Anura)

Abstract

Amphibians are susceptible to environmental pollutants and these compounds influence the development, morphology, physiology, behavior, and reproduction of these animals. Escherichia coli is common in aquatic habitats of frogs and could also damage their reproductive activity. Thus, our objective was to evaluate the effects of E. coli lipopolysaccharide on the testes of Eupemphix nattereri after 2, 6, 12, and 24 hours. As in other anurans, the testes of E. nattereri are paired structures and spermatogenesis into the locule is cystic, with mast cells in the interstitial region as well as testicular melanocytes. The administration of lipopolysaccharide decreased the absolute locular volume after 12 h while increasing the interstitial volume. In addition, lipopolysaccharide treatment decreased the absolute volume of all cell types in animals analyzed after 12 h. The amount of mast cells in the interstitial region increased after 12 h of inoculation. Acute exposure to lipopolysaccharide clearly alters testicular morphology, decreasing the volume of both locular and germ cells. However, acute treatment did not impair spermatogenesis and after 24 h, the treatment effects were minimized. Thus, this study was the first to demonstrate that lipopolysaccharide is a potential agent for causing damage to the testes of anurans.