Effects of Acute Cadmium Exposure on the Pituitary Gland of Podarcis sicula

Reptiles are rarely used in studies on the possible toxic effects of heavy metals even if they are susceptible to the accumulation of persistent pollution due also to their presence in a variety of habitats. Cadmium is a heavy metal, a significant environmental pollutant and an endocrine disruptor. Therefore the aim of this study was to analyze the cytotoxic effects of cadmium on the pituitary gland of the lizard Podarcis sicula after an acute exposure to this metal. The analysis were carried out after 2, 7 and 16 days following the intraperitoneal injection of a single and massive dose of cadmium chloride. The pituitary glands were analyzed by histological and immuhistochemical stains. Besides cadmium accumulation in brain was measured by atomic absorption spectrometry. Cadmium concentration increased in lizard brain lightly after 2 days and widely after 16 days. The tissue of the pituitary gland appeared slightly atrophied in a few areas only at 7 and 16 days after treatment. Moreover an increase in intensity of immunostaining and occurrence of some adenohypophyseal cells was revealed respect to control lizards. This evidence suggests an inhibitory effect of cadmium on the normal hormonal secretion. Evidently an acute cadmium exposure in P. sicula involves the accumulation of this metal in the brain but also the alteration of the normal endocrine function of the pituitary gland.