Oral epithelium function

Chen SY, Squier CA (1984) The ultrastructure of the oral epithelium. In Meyer J, Squier CA, Gerson SJ (eds.) The Structure and Function of Oral Mucosa. Pergamon Press, Oxford, pp 7-30... 

Wertz PW, Squier CA (1991) Cellular and molecular basis of barrier function in oral epithelium. Crit Rev Ther Drug Carrier Syst 8 237-269... 

Replacement of CTAB on the gold nanorod surface has also been achieved by in situ dithiocarbamate (DTC) formation introduced for gold surface protection, see Section 4.3.2.254 Using this protection procedure, the nonspecific uptake of nanorods by KB cells (a tumor cell line derived from oral epithelium) could be greatly reduced. Moreover, following the DTC strategy and using diamino-PEG, different functional... 

A primary function of the oral epithelium is to provide a safety barrier, to protect the oral cavity against injury. However, this protective role means that the oral epithelium also presents a considerable barrier to systemic drag delivery. 

The major function of the oral epithelium is to provide a protective surface layer between the oral environment and the deeper tissues. The oral epithelium has a squamous epithelium of tightly packed cells that form distinct layers by a process of maturation from the deeper layers to the surface. The pattern of maturation differs in different regions of the oral mucosa... 

Epithelia are essentially surface tissues of ectodermal origin. The epidermis covering the surface of the skin on the outside of the body is a typical epithelium. However, epithelia cover the surfaces of other tissues and are not necessarily confined to the outside of the animal oral epithelium and the epithelial lining of the intestine are examples of epithelia that line the wall of the alimentary canal and are kept moist by the secretion of mucous glands embedded in them. The functions of an epithelium are those that are clearly related to a superficial tissue, namely protection, absorption and secretion. The relative degree of development of these three functions varies considerably in different epithelia so that it is possible to classify these tissues according to which function predominates. 

Figure 1 Physiological model for sequential intestinal and hepatic first-pass metabolism. Blood flow to the small intestine is functionally divided into mucosal (Qgm) and serosal (Qgs) blood flow. Mucosal blood flow in the lamina propria perfuses the enterocyte epithelium. Portal blood flow (Qpv), which perfuses the liver is comprised of blood leaving the small intestine and other splanchnic organs such as the stomach and spleen. Blood flow leaving the liver (Qhv) represents the sum of hepatic arterial flow (<2ha) and Qpv. First-pass metabolism of an orally administered substrate (S) to product (P) may occur in the enterocyte or hepatocyte.

The permeability of the oral mucosal epithelium is intermediate between that of the skin epithelium, which is highly specialized for a barrier function (see Section 8.1) and the gut, which is highly specialized for an absorptive function. Within the oral cavity, the buccal mucosa is less permeable than the sublingual mucosa. 

Drug deposited on the mucous lining of the bronchial epithelium is partly absorbed and partly transported with bronchial mucus toward the larynx. Bronchial mucus travels upward owing to the orally directed un-dulatory beat of the epithelial cilia. Physiologically, this mucociliary transport functions to remove inspired dust particles. Luellmann, Color Atlas of Pharmacology All rights reserved. Usage subject to terms... 

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