Ultrastructural investigation on bovine Brunner's glands

Brunner’s glands are branched tubulo-acinar glands principally located within the lamina propria and the submucosa of the small intestine of mammals. Previous histochemical studies of Brunner’s glands in cattle have shown that the glandular lobules can be divided into two parts: a peripheral part, corresponding to the terminal tracts of the gland, and a central part, corresponding to the pre-terminal tracts and to secretory duct of the gland. Aim of our study was to perform an ultrastructural investigation to verify whether the histochemical partition of the gland corresponded to the presence of different cell types, as described in other species. Data demonstrated that the glands were formed by two cell types: the tubulo-acinar gland regions consisted of pyramidal cells with large electron-lucent mucous secretory vesicles, while the pre-terminal and secretory ducts were made of sero-mucous cells with variable number of discrete secretory vesicles of different electron-density.