Adenohypophyseal cells alterations in cadmium treated lizards Podarcis sicula

Cadmium (Cd) is known as a potent toxic metal and a significant environmental pollutant. It has been shown that Cd is an endocrine disruptor that may play a role in the etiology of the pathology that involves the hypothalamic-pituitary-testicular axis. In the present work we have examined the cytotoxic effects of Cd on the pituitary gland of the lizard Podarcis sicula after an oral treatment carried out for 120 days by dose of 1mg/Kg-BW. At optical microscopy the pituitary gland of the treated lizards showed a damaged aspect: the tissue appeared atrophied in some areas, with large and irregular intercellular spaces and with several cells altered in the shape. By ABC technique, we have also revealed significant alterations of PRL, ACTH and GTH cells; while for GH and MSH cells have not been observed remarkable changes in confront of the same cells of control animals. After 30 days PRL and FSH cells appeared increased in number and in immunostain, extended also to the Caudal Pars Distalis. ACTH and LH cells appeared indeed increased and strongly marked after 60 days of treatment. In lizards, a protracted exposition to cadmium involves evidently inhibitory effect on the hormonal secretion of the pituitary gland because PRL, ACTH and GTH cells increase in number and in immunostaining intensity. The physiological significance of these effects remains to be elucidated; it could be due to the fact Cd affects calcium homeostasis plays an important role in the adenohypophyseal secretion.