Biochemical Composition of Human Saliva in Relation To Other Mucosal Fluids

Abstract

This paper describes several salivary components and their distribution in other mucosal secretions. Histatins are polypeptides which possess exceptional anti-fungal and anti-bacterial activities, but are nevertheless present only in saliva. Proline-rich proteins (PRPs) are members of a closely related family, of which the acidic PRPs are found solely in saliva, whereas the basic PRPs are also found in other secretions. Mucins are a group of glycoproteins that contribute to the visco-elastic character of the mucosal secretions. Despite the similarities in their structure and behavior, mucins have distinct tissue distributions and amino acid sequences. Other salivary proteins are present in one or more mucosal secretions. Lysozyme is an example of a component belonging to an ancient self-defense system, whereas secretory immunoglobulin A (sIgA) is the secreted part of a sophisticated adaptive immune system. Cystatins are closely related proteins which belong to a multigene family. Alpha-Amylase is a component that is believed to play a specific role in digestion, but is nevertheless present in several body fluids. Kallikrein and albumin are components of blood plasma. But whereas albumin diffuses into the different mucosal secretions, kallikrein is secreted specifically by the mucosal glands. The presence of these proteins specifically in saliva, or their distribution in other mucosal secretions as well, may provide important clues with respect to the physiology of those proteins in the oral cavity.

Candidiasis: Predisposing Factors, Prevention, Diagnosis and Alternative Treatment

“…This is the case of some increasing prevalence diseases, such as cancer, diabetes, and hypothyroidism, that in addition to debilitate immune system of individuals, has led to a continuous and exacerbated prescription of immunosuppressant drugs [1,11,17,18,24,37,40,41,[67][68][69].…”

Innate Secretory Immunity in Response to Laboratory Stressors That Evoke Distinct Patterns of Cardiac Autonomic Activity

“…The relevance of these observations may not be limited to the dental sciences, because impaired oral health is a risk factor in cardiovascular disease and respiratory infection (25)(26)(27)(28). Last but not least, saliva contains many of the antimicrobial proteins also found in other mucosal secretions (4), which makes saliva a representative model for studying secretory immunity.…”

“…An estimated 90% to 95% of all infections are initiated at mucosal surfaces, which form an interface with the outside world. These surfaces are covered and protected by the secretions of various exocrine glands, including the lacrimal glands (3,4), the salivary glands (4 -7), and the glands of the respiratory (6, 8 -11) and gastrointestinal tract (4,6,(12)(13)(14). The antimicrobial proteins (eg, mucins, cystatins, histatins, and lactoferrin) secreted by these glands constitute a first line of defense, preventing infection and disease by interfering with microbial entry and multiplication (3, 4, 6 -8, 11-15).…”

Salivary MUC5B-Mediated Adherence (Ex Vivo) of Helicobacter pylori During Acute Stress

“…Infections are often initiated at mucosal surfaces, which form a boundary with the outside world. Host defense at mucosal surfaces is mediated by both nonspecific and immunologically specific mechanisms (3)(4)(5). Several studies in psychoimmunology have utilized S-IgA as an index of specific mucosal immune function (6).…”