Ultrastructural study of the prolactin and somatotroph cells in Chalcides chalcides (Squamata: Scincidae)

The introduction of immunocytochemistry practice has certainly favoured the comparative histological studies. This procedure has also simplified the study of the pituitary gland with a precise identification of the different cellular types and supplanting definitively the classic stains. However studies about reptilian pituitary are still scarce when compared to other classes of vertebrates. As a development of our previous studies, in this paper we report the ultrastructural study of prolactin and somatotroph cells in the pituitary gland of the viviparous reptile Chalcides chalcides by immunogold technique. Although the somatotroph cells are larger than the prolactin cells, they are characterized by the presence of secretory granules of 180-220nm in diameter that are smaller than the granules of the other cellular type with a diameter of 250-350nm. In both cell types the granular material is for the most homogenous. These results show that prolactin and somatotroph cells are two distinct different cell types in according with that we have reported by the light microscopy.