“Testicular concentrations of metals and metalloids in dogs from the ‘Land of Fires’ (Campania Region, Italy): A preliminary morphological, chemical and molecular study”

In Campania Region, an area known as the 'Land of Fires', has been described as an open-air dump due to the illegal discharges of toxic substances. The dog (Canis familiaris) represents a useful sentinel for tracking environmental risks. To this aim, fifty male stray dogs were enrolled, and testicular samples were processed for histological, chemical and molecular analyses. The animals were classified into four groups, from normal spermatogenesis to intratubular seminoma. Inductively coupled plasma mass spectrometry (ICP-MS) was conducted to assess metal and metalloid concentrations. Collagen deposition was assessed by Masson's trichrome and Picrosirius red staining. Immunohistochemistry and Western blot analyses were carried out to evaluate 17β-hydroxysteroid dehydrogenase (17β-HSD), Cytochrome P450 aromatase (P450), and the Proliferating Cell Nuclear Antigen (PCNA). Chemical analysis revealed significant group differences for cadmium, nickel and uranium levels across all histological groups. These findings suggest a distinct testicular profile, with differential metal accumulation by lesion severity and altered steroidogenic and proliferative processes.