Structural Features of the Cardia Gastric Region in Domestic Rabbits

Abstract

The knowledge of normal microscopical peculiarities of the digestive system in mammals is essential, but information regarding certain structures is still scarce in numerous species. Our study aims to highlight the normal morphological features of the cardia region in domestic rabbits, as regards the overall appearance, structure, and dimensions of the gastric pits, including a description of the cells located in gastric glands. The cardia region of five domestic rabbits underwent tissue sampling, followed by fixation in 10% buffered formalin, paraffin embedding, and later sectioned at 5 µm in thickness. Eventually, the samples were stained by Goldner’s trichrome method. The microscopical examination has revealed the presence of gastric pits and glands in the entire cardia region of the rabbit, with a different morphological appearance from one zone to another. Gastric pits have the smallest depth immediately after the oesophagogastric junction, which gradually increases and decreases afterwards as it approaches the fundic zone. The gastric glands contain basically four cell types in various proportions, including serous cells, mucous cells, parietal cells, and chief cells. Other peculiarities of the gastric mucosa in the cardia region in rabbits include a thick mucosa with a loose and prominent lamina propria, and an ill-defined muscularis mucosae that is not organized in distinct layers as in other species. The detailed microanatomical structure of the cardia region of the stomach is necessary for understanding the digestion processes in rabbits, species used as a model in diverse fields of research including the pathology of the digestive system.