Immunodetection of aquaporin 5 in sheep salivary glands related to pasture vegetative cycle

Abstract

Mammalian aquaporins (AQPs) are a family of at least 13 integral membrane proteins expressed in various epithelia, where they function as channels to permeate water and small solutes. AQP5 is widely expressed in the exocrine gland where it is likely involved in providing an appropriate amount of fluid to be secreted with granular contents. As regards AQP5 expression in the salivary glands, literature is lacking concerning domestic animal species. This study was chiefly aimed at immunohistochemically investigating the presence and localization of AQP5 in sheep mandibular and parotid glands. In addition, AQP5 immunoreactivity was comparatively evaluated in animals fed with forage containing different amounts of water related to the pasture vegetative cycle, in order to shed light on the possible response of the gland to environmental modifications. Moderate AQP5-immunoreactivity was shown at the level of the lateral surface of mandibular serous demilune cells, not affected by the pasture vegetative cycle or water content. On the contrary, the parotid gland arcinar cells showed AQP5-immunoreactivity at the level of apical and lateral plasma membrane, which was slight to very strong, according to the pasture vegetative development and interannual climatic variations. AQP5 expression is likely due to its involvement in providing appropriate saliva fluidity. Indeed, the lowest AQP5 immunoreactivity was noticed when food water content increased

Comparison between two different methods for evaluating rumen papillae measures related to different diets

“…In this regard, it is noteworthy that the significance is greater in the moment of maximum flowering in 2008, a particularly rainy year, when compared with the same moment in 2007, an especially dry year, when the phytomass produced was qualitatively and quantitatively inferior; differences linked to interannual climatic variations have been described for both sheep rumen mucosa (surface enlargement factor and keratinization degree) and salivary glands (Ceccarelli et al, 2009;Scocco et al, 2009Scocco et al, , 2011. In addition, the reduction of absorption function is further supported by the modification of both the calibre and number of blood vessels at rumen tunica propria submucosa level (see Fig.…”

The expression of water channel proteins during human salivary gland development: a topographic study of aquaporins 1, 3 and 5

“…In larger mammals, Scocco et al ( 2011 ) identified AQP5 in adult sheep mandibular and parotid salivary glands. In the parotid, they observed AQP5 at the lateral and apical membranes of acinar cells, also correlating its higher expression when feeding the animals according to water content food.…”

Immunolocalization of Aquaporin Water Channels in the Domestic Cat Male Genital Tract

“…) and ovine salivary gland (Scocco et al. ). Sections of rat organs similarly processed as above served as positive controls for AQP1 (kidney, Fig.…”