What is in rat saliva? - briefly
Rat saliva comprises water, electrolytes, enzymes such as amylase, antimicrobial peptides, and a range of proteins including growth factors. It also contains trace metabolites and metal ions that affect oral microbiota and digestion.
What is in rat saliva? - in detail
Rat saliva is a complex fluid whose composition reflects the animal’s physiology, diet, and oral microbiota. The major constituents are:
- Water – accounts for 95–99 % of the volume, providing a medium for solutes.
- Electrolytes – sodium, potassium, chloride, calcium, magnesium, and bicarbonate ions maintain osmotic balance and pH regulation.
- Proteins and enzymes – include α‑amylase (carbohydrate digestion), lysozyme (bacterial cell‑wall hydrolysis), carbonic anhydrase (acid‑base control), and lactoperoxidase (oxidative antimicrobial activity). Salivary mucins contribute to lubrication and form a protective gel layer on oral surfaces.
- Immunoglobulins – predominantly IgA, offering mucosal immunity against pathogens; IgG and IgM appear in lower concentrations during infection or stress.
- Hormones and neuropeptides – measurable levels of corticosterone, adrenaline, and vasoactive intestinal peptide indicate systemic stress responses and influence salivary flow.
- Metabolic markers – glucose, urea, and creatinine reflect systemic metabolic status; elevated glucose may signal hyperglycemia, while urea concentrations correlate with renal function.
- Trace elements – zinc, copper, and iron are present in micromolar amounts, supporting enzymatic activity and antimicrobial defenses.
- Microbial metabolites – short‑chain fatty acids and volatile compounds arise from oral microbiota metabolism, contributing to odor and signaling.
Composition varies with age, sex, nutritional state, and health condition. For example, lactating females exhibit increased prolactin and altered protein profiles, while infected rats show elevated lysozyme and IgA concentrations. Analytical techniques such as mass spectrometry, high‑performance liquid chromatography, and enzyme‑linked immunosorbent assays provide quantitative data on these components, enabling research on disease biomarkers, toxicology, and comparative physiology.