Browsing by Subject "Bicarbonate"

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    Automated Spectrophotometric Assays for the Measurement of Ammonia and Bicarbonate in Saliva of Horses: Analytical Validation and Changes in Equine Gastric Ulcer Syndrome (EGUS)
    (MDPI, 2024-02-28) Muñoz-Prieto, Alberto; Llamas-Amor, Eva; Contreras-Aguilar, María Dolores; Ayala de la Peña, Ignacio; Martín Cuervo, María; Cerón, José Joaquín; Hansen, Sanni; Medicina y Cirugía Animal
    Ammonia (NH3) and bicarbonate (HCO3) have been related to gastric ulcers in humans. Ammonia is considered a possible cause of gastric ulcers, whereas bicarbonate has a protective function. The presence of ulcers in the stomach of horses is defined as Equine Gastric Ulcer Syndrome (EGUS), which is a frequent disease in this species, and it has been associated with changes in saliva composition, such as in analytes related to inflammation, immune system and oxidative stress. The objectives of this study were (1) to perform an analytical validation of two automated spectrophotometric assays, one for ammonia and one for bicarbonate, in the horses’ saliva and (2) to evaluate their possible variations with EGUS. Analytical validation of the automated assays for ammonia and bicarbonate in the saliva of horses showed that both assays were precise and accurate. In addition, significantly higher values of ammonia and lower values of bicarbonate were found in the saliva of horses with EGUS compared to healthy horses. It can be concluded that ammonia and bicarbonate can be measured in the saliva of horses and that ammonia increases and bicarbonate decreases in this sample type could be related to the presence of EGUS in this species.
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    Salivary gland carbonic anhydrases
    (Servicio de Publicaciones, Departamento de Histología e Histopatología, 2025) Redman Robert S.; Biología Celular e Histología
    Carbonic anhydrases (CA) are zinc metalloenzymes that catalyze the reversible conversion of carbon dioxide and water to bicarbonate. For most mammalian cells, this reaction is essential to maintaining intracellular physiological pH. For salivary glands, it also has an important role in the regulation of the pH and buffering capacity of their secretory product, saliva, which is central to the activity of salivary digestive enzymes. This review is a chronological narrative of the discovery and distribution of CA and its isoenzymes in mammalian salivary glands and saliva and the role of CA in regulation of salivary pH via secretion of the salivary CA isoenzyme and the secretion and reabsorption of bicarbonate from the ductal lumen. The interaction of sodium/bicarbonate co-transporters and other factors in these processes is briefly described. The distribution of CA among mammalian species, salivary glands, and gland cells as determined by CA activity in saliva and gland extracts, enzyme histochemistry, and immunohistochemistry is presented in tables. The importance of salivary CA to oral health is underscored by the reduction in salivary gland and salivary CA activity by nutritional zinc deficiency and genetic variants of two of the CA isoenzymes, which cause dysgeusia and hyposalivation and are associated with increased dental caries