Fine structureof rat exorbital gland after orchiectomy

INTRODUCTION & AIM The exorbital lacrimal gland (ELG) (gl. Loewenthali)1 of the rat is situated close to the parotid gland and shows sexual dimorphism, i.e., different histological appearance in males and females2. The present study was designed to establish the effects of orchiectomy on the acinar structure of this gland in the adult male rat. MATERIALS & METHODS Adult male Fischer rats were divided into 3 major gropus: intact controls, sham-operated and orchiectomized (experimental) group of animals. Experimental group was subjected to a bilateral orchiectomy and sacrificed after the following periods of time: 12 hours, 3, 7, 14, 30, 60, 90 days. The same procedure & timing was applied for sham-operated animals and intact controls. After the mild ether anaesthesia, ELGs were removed form the parotid region, fixed in 4% buffered glutaraldehyde and postfixed in 1% OsO4. After dehydration, the tissue samples were embedded in Durcopan. Durcopan blocks were cut by the Reichert ultramicrotome. Semi-thin and ultra-thin sections were made. Ultra-thin sections were placed on copper grids and contrasted with lead citrate and uranyl acetate and examined by transmission electron microscopy. RESULTS Acinar cells of control and sham-operated animals were pyramidal in shape, with usually centrally positioned nucleus of round or ovoid shape. Within the cytoplasm of these cells, abundant cisternae of rough endoplasmic reticulum and well-developed Golgi apparatus could be noticed (Fig.1). Occasional secretory granules of moderate electron density were also observed. The acinar cells of orchiectomized rats displayed significant polymorphism with excentrically located nucleus. Their cytoplasm was sometimes flattened, thus giving the acini of the gland a “ pseudofollicular” shape. Moreover, the cytoplasm of these cells was filled with numerous secretory granules and vacuoles of low or moderate electron density (Fig 2). The appearance of “ pseudofollicles” was more frequent in experimental groups of animals 30, 60 and 90 days after castration. CONCLUSION Orchiectomy affects the fine structure of the ELG acini. The observed changes of acinar cells at ultrastructural level, especially flat cell shape, formation of “ pseudofollicles” and accumulation of secretory granules and vacuoles suggest metabolic changes caused by the testosterone deprivation. The testosterone deprivation very likely induced a decrease in EGF levels, important for maintenance of the acinar cells function.