Expression of dystrophins and the dystrophin-associated-protein complex by pituicytes in culture.

The dystrophin-associated-protein complex (DAPC) has been extensively characterized in the central nervous system where it is localized both in neuronal and glial cells. Few studies have characterized this complex in the neurohypophysis. To further study this complex in pituicytes, the resident astroglia of the neurophypophysis, we used adult pituicyte cultures and determined the expression and localization of dystrophins/utrophins and the DAPC by RT-PCR, western blotting and immunofluorescence. Our data show that the pituicytes express dystrophins, utrophins and several members of the DAPC including dystroglycans, δ-, γ-sarcoglycans, α-dystrobrevin-1 and α1-syntrophin. Double immunofluorescence analysis shows that laminin colocalizes with dystroglycan, suggesting that similarly to muscle and astrocytes, the DAPC interacts with the extracellular matrix in pituicytes. Collectively these findings show that dystrophins/utrophins and members of the DAPC are expressed in pituicytes where they may form multiprotein complexes and play a role in the retraction-reinsertion of pituicyte endfeet during specific physiological conditions.

Structural study and expression of the androgen receptors during the reproductive cycle in the Harderian gland of the male Meriones libycus.

The goal of this study was to evaluate for the first time the expression of the androgen receptors (AR) in Harderian glands (HG) of the male Meriones lybicus in relation to the reproductive cycle. Six male Harderian glands of the resting period and 6 of the breeding period were collected. The animals were trapped in the desert of Béni Abbès (Algeria). The morphology of the Harderian glands was studied by light microscopy and morphometry, whereas the expression of the androgen receptors was assessed and quantified based on immunohistochemistry techniques. We have shown that the Harderian glands of Meriones libycus are tubuloalveolar glands with wide lumen. The glandular epithelium is composed of two types of cells (types I and II) in the resting season and three types of cells (types I, II and III) in the breeding season. These three types of cells differ in size and shape. Type-I cells have a prismatic shape, an acidophilic cytoplasm, and small lipidic vacuoles, whereas type-II ones are pyramidal in shape, with basophilic cytoplasm. Type-III cells resemble those of type I, and so they are prismatic in shape and have an acidophilic cytoplasm with larger lipidic vacuoles. The immunoreactivity of type-I and type-III cells was mainly cytoplasmic and the intensity of the immunostaining was significantly higher during the breeding season. Among other functions, the Harderian gland seems to be involved in the production of pheromones under the effect of androgens.