Cadmium effects on PRL cells in the pituitary gland of Podarcis sicula

In spite of their important role as bioindicators there is few information about the cytotoxic effects of cadmium at the pituitary level in reptilian species. In order to fill this gap, we have studied the possible morphological changes induced from CdCl2 on the prolactin cells in the pituitary gland of Podarcis sicula. Two types of experiments were carried out: a group of lizards were exposed to an acute treatment by an intraperitoneal injection of a single and massive dose (2mg/Kg-BW) of CdCl2; another one was indeed treated for four months with CdCl2 at dose of 1mg/Kg-BW in the drinking water (chronic treatment). Serial sections of 6 µm of the pituitary gland were processed for routine histological and immunohistochemical staining by ABC technique. The cytotoxic effects of cadmium were more evident on the PRL cells of P.sicula of the chronic treatment. In fact, in the lizards at 2, 7 and 16 days of the acute treatment, few differences was revealed in the shape, number and distribution of these cells respect at the same cells of control animals. In the PRL cells of the chronic treatment indeed we observed significant difference: during the treatment a meaningful increase in number of PRL cells was appreciate just at 30 days; the cells appeared in the rostral and medial pars distalis, like in the control specimens, but also in the caudal pars distalis with an increase in immunostaining intensity. In lizards, a protracted exposition to cadmium involves evidently an inhibitory effect on the PRL secretion as in the rat through an interaction with the prolactin molecule, that is sensitive to divalent metals as was shown in vitro.