Cadmium Induces Apoptosis in the Pituitary Gland of <i>Podarcis sicula</i>

Abstract

The cytotoxic effects of cadmium (Cd) on the pituitary gland were studied in the lizard Podarcis sicula. Adult lizards were treated intraperitoneally with a single injection of CdCl(2) at the dose of 2 mg/kg. A morphological study was performed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique and by immunocytochemical demonstration of caspase-3 for detecting apoptotic cells in situ after 2, 7, and 16 days of treatment. The pituitary cells of Cd-treated P. sicula undergo apoptosis: after 2 days the apoptotic cells appeared to increase significantly compared with those of the control specimens; after 7 days there was no considerable increment; however, after 16 days the occurrence of apoptotic cells had increased markedly, above all in the rostral pars distalis (RPD) in which various cells showed a strongly immunostained nucleus by TUNEL. Cd appears particularly toxic for pituitary cells in the lizard P. sicula; a single high intraperitoneal dose of CdCl(2) induces apoptosis, in particular in the RPD, and this effect appears irreversible.