Mucus constituents

It has recently been discussed [61-63] whether the diffusional barrier at the intestinal surface can be accounted for solely by an unstirred water layer. It has been proposed that the mucus layer overlying the enterocytes should be regarded as an important diffusion barrier for uptake of lipid solutes from the luminal contents. The mucus adherent to the rat duodenal wall has been found to be approximately 80 jam thick in the fasted state [64]. The intestinal mucus coat is formed by proteoglycans produced by goblet cells, but so far very little is known about the molecular structure of the mucus layer [65]. The possible interaction between mucus constituents and luminal lipid solutes needs to be investigated in detail, since it might reveal key factors which constitute the diffusional barrier of the small intestine. 

Burger, O., Weiss, E., Sharon, N., Tabak, M., Neeman, I., and Ofek, I. (2002). Inhibition of Helicobacter pylori adhesion to human gastric mucus by a high-molecular-weight constituent of cranberry juice. Grit. Rev. Food Sci. Nutr. 42, 279-284. 

Mucus exists in the form of a viscous solution or a gel and is a sticky viscoelastic substance with water as its major constituent, accounting for 95 to 99.5 percent.101 Mucins are large (MW range 1000 to 40,000... 

Initial attempts at selecting PEs have identified certain surfactants, such as bile salts and fatty acids, which appear to facilitate oligonucleotide absorption. The advantages of these components are many, in that they are endogenous to foods and body constituents, plus the literature is rich with information about the use and exposure of these two classes of compounds [56]. The precise mechanism of action for these PEs is unknown, but is believed to involve a disruption of the mucus layer barrier, an increase in the fluidity of the mucosal membrane, and potentially an opening of the paracellular tight junctions. The mucolytic effect coupled with the increased membrane fluidity imparted by these excipients appears to allow in-... 

A review of analyses of the composition of mucus indicated that protein makes up 4—49% of the coral organism with total N making up 0.04—5.2% of mucus (Brown and BytheU, 2005). The primary constituents of the mucus matrix are glycoproteins or mucins. In a recent model of the mucus layer, organic exudates and organic N are released from the coral surface and go on to support a dynamic microbial community within the mucopolysaccharide layer around the coral (Rohwer and KeUey, 2004). 

Oral administration is the most common route of drug administration. Major physiologic processes in the GI system include secretion, digestion, and absorption. Secretion includes the transport of fluid, electrolytes, peptides, and proteins into the lumen of the alimentary canal. Enzymes in saliva and pancreatic secretions are involved in the digestion of carbohydrates and proteins. Other secretions such as mucus protect the linings of the lumen of the GI tract. Digestion is the breakdown of food constituents into smaller structures in preparation for absorption. Both drug and food constituents are mostly absorbed in the proximal area (duodenum) of the small intestinal. The process of absorption is the entry of constituents from the lumen of the gut into the body. Absorption may be considered as the net result of both lumen-to-blood and blood-to-lumen transport movements. 

ADHATODA The leaves of Adhatoda vasica, Nees, family Acanthaceae, are used in India. The constituents include the alkaloid vasicine (peganine), which has a mucolytic effect, i.e. lowers the viscosity of the bronchial mucus by depolymerisation and makes it more liquid, so that it can be transported. The mucocilliary transport of mucous to the periphery depends on the mucous having certain rheological properties. The drug is used as mucolytic in cough mixtures in the form of a liquid extract. 

The viscous and gel-forming properties of mucus secretions are derived from mucin glycoprotein constituents (5%) they also contains protein, lipid and nucleic acid, much of it derived from dislodged epithelial cells and bacteria [199]. These constituents have been shown to enhance the viscous properties of mucins in vitro [200, 201], and such interactions may be significant towards determining mucus gel properties in vivo. 

Falk, H.L., H.M. Tremer, and P. Kotin Effect of cigarette smoke and its constituents on ciliated mucus-secreting epithelium J. Natl. Cancer Inst. 23 (1959) 999-1012. 

Mucins A secretion containing mucopolysaccharides and protein that is the chief constituent of mucus. [NIH]... 

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