Anna Maria Gargiulo

Histology and Ultrastructure of the Gut of the Tilapia (Tilapia spp.), a Hybrid Teleost

The morphology of the intestine has been studied in a species of warm water fish, Tilapia spp., a hybrid teleost of notable economic importance. Light and electron microscope results show that the intestine is a relatively undifferentiated muscular tube lined with a simple columnar epithelium interspersed with goblet cells. The proximal region has a greater surface area, manifested by elongated mucosal ridges. The enterocytes are covered apically with uniform microvilli and exhibit the typical ultrastructural features of pinocytosis, namely extensive invaginations of the luminal plasma membrane and massive accumulation of vesicles in the apical cytoplasm. The distal intestine mucosa is thinner and less elaborately folded and consists of columnar cells with shorter and sparser microvilli. Their supranuclear cytoplasm contains abundant clear vacuoles. Numerous endocrine cells can also be seen. Regional cellular ultrastructural features are correlated with digestive functions.

Ultrastructural Study on the Stomach of Tilapia spp (Teleostei)

An ultrastructural study has been made of gastric mucosa of a teleostean fish, Tilapia spp. The cytological features of the surface mucous cells, mucous neck cells, glandular cells and endocrine cells are described. The surface mucous cells, identified by their superficial localization, are characterized by apical granules. The mucous neck cells are distinguished by the appearance of their mucous granules and their localization between surface mucous cells and glandular cells. The gastric glands contain only one form of cell whose fine structure is similar to cells that secrete hydrochloric acid.

The Endocrine Cells in the Gastro‐enteric Tract of Adult Fallow Deer (Dama dama L.)

Endocrine cells were detected in the gastro‐enteric tract of the fallow deer by means of immunohistochemical procedures, using antibodies against serotonin, somatostatin, gastrin, glucagon and cholecystokinin. The number of cells positive for each antiserum in each region was evaluated. Serotonin‐containing enterochromaffin (Ec) cells were present in every region investigated and were most numerous in the proximal duodenum. Cells positive for somatostatin were present in all the regions studied, with the exception of the colon, and were especially numerous in the proper gastric‐gland region. Cells that were stained by the anti‐gastrin antibody were very numerous in the pyloric‐gland region but only rare in the duodenum. Glucagon‐immunoreactive cells were only detected in the large intestine and their frequency was always less than 10/0.5 mm2. Cholecystokinin‐containing cells were scarce and restricted to the pyloric‐gland region and duodenum.

Serotonin-Containing Cells in the Horse Gastrointestinal Tract

The presence and distribution of serotonin‐containing cells in the gastroenteric tract of horses have been investigated. The enterochromaffin (EC) cells have been identified using immunostaining procedures at both light and electron microscopic level. The EC cells were very numerous in the pyloric gland region, were only few in the duodenum but were absolutely lacking from the more distal portions of the intestine.

Carbohydrate histochemistry of lamb duodenum

In order to elucidate the carbohydrate profile of the mucosa of lamb duodenum, conventional histochemical methods and a panel of 7 labelled lectins were used. In some cases, treatment with sialidase preceeded lectin staining. Carbohydrate histochemistry revealed the presence of sugar residues in the brush border of enterocytes, goblet cells and duodenal glands. All sites contained neutral and acid glycoconjugates. The presence of sulphomucins in goblet and duodenal gland cells was age-dependent. Enterocytes and duodenal gland cells contained abundant amounts of oligosaccharides with terminal sialic acid-galactosyl(beta1 --> 3)N-acetylgalactosamine, whereas goblet cells contained the penultimate N-acetylgalactosamine residue linked to sialic acid. These findings were not age-dependent, whereas scarce amounts of fucose were found in all sites especially in young animals. The findings obtained in the present study serve as a basis for future pathological studies in lamb and sheep.

Complex Carbohydrate Histochemistry and Ultracytochemistry of the Sheep Lacrimal Gland

The chemical content of the secretion of the sheep lacrimal gland was analysed at the light and electron microscope levels by applying histochemical techniques and an ultrastructural histochemical method (periodic acid, thiocarbohydrazide and silver proteinate). Mucosubstance histochemistry demonstrated acidic glycoconjugates, mainly sulphated, in the mucous and seromucous glandular cells and in the apical portion of the cells lining the terminal ducts. Moreover, secretory granules, stained with PA‐TCH‐SP, showed a different localization of the reaction product. The presence of lysozyme was also found in the glandular serous cells. These histochemical studies demonstrate that the secretion of sheep lacrimal glands is mixed, having serous, mucous and seromucous components, and that an excellent correlation exists between the secretory granule substructure and glycoprotein localization.

Immunohistochemical localization of cyclic AMP and ultrastructural demonstration of adenylate cyclase activity in the testis of Esox lucius at time of spermiation

SummaryIn the testis of Esox lucius at the time of spermiation, activity of cyclic adenosine 3′,5′-monophosphate (cAMP) was immunocytochemically localized at the level of the Sertoli cells. In these cells adenylate cyclase activity was also ultracytochemically demonstrated by using adenylyl imidodiphosphate as a substrate. Reaction products of adenylate cyclase were primarily detectable on the basal and adluminal plasma membranes and on the surface of protrusions of the cell body into the lumen.

Basic and Lectin Histochemical Characterization of Bovine Gustatory (von Ebner's) Glands

The Bovine tongue possesses numerous circumvallate papillae (8–16) each side). The troughs around the papillae are the openings of the ducts of the gustatory (von Ebners) glands.

Lectin histochemical study of bovine lingual glands

Bovine lingual glands consist of mucous acini capped by demilunes. Information on the chemical structure of their secretory glycoconjugates was obtained by means of a battery of peroxidase-conjugated lectins with affinity for specific terminal sugars. Sialidase procedures followed by lectin staining were also used to visualize the sugar sequences. Stored secretions in mucous acinar cells contained fucose, N-acetylglucosamine, alpha and beta-N-acetylgalactosamine as terminal sugar residues and beta-galactose as penultimate sugar in a heterogeneous distribution. Demilunar cells failed to react with any of the lectins examined except that of Dolichos biflorus.

Immunohistochemical Localization of Endometrial Oestrogen and Progesterone Receptors in the Cow

The presence and distribution of oestrogen and progesterone receptors have been investigated by means of immunohistochemical procedures in the uterus of two groups of cows: the first group underwent superovulatory hormonal treatment while the second group was used as a control group. After the immunohistochemical study no differences regarding the presence and distribution of hormone receptors seemed to be apparent between the two groups, so it was concluded that the topographical distribution and staining intensity of hormone receptors seem to be unaffected by hormonal superovulatory treatment.