First evidence of histological and histochemical intraspecific differences in salivary glands in Brown Norway and albino Wistar rats*

Abstract

The size of salivary glands, acinar structure, and secretion particularities differ from one species to another and are influenced by diet and environment. In order to investigate whether there are histological or histochemical differences in the salivary glands of animals from the same species, bred in identical conditions of environment and diet, we assessed two laboratory rat strains. The salivary glands from two rat strains were processed for histological and histochemical investigations. Histologically, we noticed differences in the parotid gland: seromucous acini were present in Brown Norway rat and typical serous ones in Wistar rat. Histochemically, we observed that cells in the parotid gland present a moderate PAS-positive reaction only in Wistar rat. In the mandibular gland, the size and shape of the acini were similar, whereas the cytoplasm of acinar and granular duct cells was PAS-positive in both rat strains, but with different intensities. In the sublingual gland, both PAS and Alcian blue reactions were positive in the two rat strains, with a higher intensity in the Brown Norway strain. Our study highlighted intraspecific histological and histochemical differences in salivary glands from two rat strains bred and fed in identical conditions.

Microanatomical, histochemical and morphometric features of the major and selected minor salivary glands in laboratory Wistar rat

“…Even if all the salivary glands share a common purpose, that is, the production of saliva, the microanatomy varies from one gland to another and from one species to another. Accordingly, the structure of the parotid gland in Wistar rat is mostly similar to the one described in mice and chinchilla, but different from that of the rabbit, guinea pig and even the Brown Norway rat (Ruxanda et al., 2018). In our results, histological and histochemical features suggested a serous secretion for the parotid gland (i.e.…”

Comparative Histology and Histochemistry of the Parotid Gland and Mandibular Gland in the Lowland Tapir (Tapirus terrestris Perissodactyla) and Aardvark (Orycteropus afer Tubulidentata)

“…The histological structure of the individual salivary glands and the share of serous and mucous cells in their architecture varies depending on the diet and the environment in which the animal lives [18][19][20][21].…”

“…In animals, both diet and habitat influence the size of the glands of the oral cavity, the structure of secretory units, and the nature of their secretion (serous, mucous, or mixed). For example, in herbivores, the parotid gland is larger, and the serous parotid secretion is more copious [1,[18][19][20][21].…”