Nasal mucus

Nasen-. (Physiol.) nasal, naso-. -bluten, n. nosebleed, epistaxis. -loch, n., -offnung, /. nostril, -racheorelzstoff, m. nose and throat irritant, sternutator. -reizstoff, m. nose irritant, sternutator, -schlacke, /. (Metal.) tuyere (twyer) slag, -schleim, m. nasal mucus, -schleimhaut, /. mucous membrane of the nose. 

Table 3.1 for the putative carriers in saliva, urine and nasal mucus the N-terminal sequences are highlighted against the pig salivary protein. All lipocalins or similar uncharacterised ( 20kDa) fractions with biological activity are extracellular, often found in quantity, 5 g/ml protein in male mouse urine and with a relatively high negative charge. 

Local host defenses of both the upper and lower respiratory tract, along with the anatomy of the airways, are important in preventing infection. Upper respiratory defenses include the mucodliary apparatus of the nasopharynx, nasal hair, normal bacterial flora, IgA antibodies, and complement. Local host defenses of the lower respiratory tract include cough, mucodliary apparatus of the trachea and bronchi, antibodies (IgA, IgM, and IgG), complement, and alveolar macrophages. Mucus lines the cells of the respiratory tract, forming a protective barrier for the cells. This minimizes the ability of organisms to attach to the cells and initiate the infectious process. The squamous epithelial cells of the upper respiratory tract are not ciliated, but those of the columnar epithelium of the lower tract are. The cilia beat in a uniform fashion upward, moving particles up and out of the lower respiratory tract. 

Penetration enhancers are low molecular weight compounds that can increase the absorption of poorly absorbed hydrophilic drugs such as peptides and proteins from the nasal, buccal, oral, rectal, and vaginal routes of administration [186], Chelators, bile salts, surfactants, and fatty acids are some examples of penetration enhancers that have been widely tested [186], The precise mechanisms by which these enhancers increase drug penetration are largely unknown. Bile salts, for instance, have been shown to increase the transport of lipophilic cholesterol [187] as well as the pore size of the epithelium [188], indicating enhancement in both transcellular and paracellular transport. Bile salts are known to break down mucus [189], form micelles [190], extract membrane proteins [191], and chelate ions [192], While breakdown of mucus, formation of micelles, and lipid extraction may have contributed predominantly to the bile salt-induced enhancement of transcellular transport, chelation of ions possibly accounts for their effect on the paracellular pathway. In addition to their lack of specificity in enhancing mem-... 

Lysozyme is an enzyme in nasal mucus that fights infection by degrading bacterial cell walls. 

Radon daughters are deposited on the surface of mucus lining the bronchi. It is generally assumed that the daughter nuclides, i.e. polonium-218 (RaA), lead-214 (RaB) and bismuth-214 (RaC), remain in the mucus and are transported towards the head. However, one dosimetric model assumes that unattached radon daughters are rapidly absorbed into the blood (Jacobi and Eisfeld, 1980). This has the effect of reducing dose by about a factor of two. Experiments in which lead-212 was instilled as free ions onto nasal epithelium in rats have shown that only a minor fraction is absorbed rapidly into the blood (Greenhalgh et al., 1982). Most of the lead remained in the mucus but about 30% was not cleared in mucus and probably transferred to the epithelium. 

Exposure to hexachloroethane vapors can cause irritation to the respiratory system. Acute exposure to 260 ppm hexachloroethane had no apparent effect on the lungs and air passages in rats, but acute exposure to a concentration where particulate hexachloroethane was present in the atmosphere caused lung irritation (Weeks et al. 1979). On the other hand, intermediate-duration exposure to 260 ppm hexachloroethane appeared to cause some irritation of the respiratory epithelium, which may have increased susceptibility to respiratory infection. When exposure ceased, the animals recovered, so there were no histopathological indications of tissue damage after a 12-week recovery period. Lesions of the nasal passages, trachea, and bronchi increased mycoplasma infections mucus in the nasal cavities and decreased oxygen consumption were indicators of respiratory tract irritation from repeated episodes of hexachloroethane exposure. 

Excess mucus in the nasal turbinates, irritation of the epithelium, and increased incidence of a mycoplasma respiratory infection were seen in rats with inhalation exposure to 260 ppm for 6 weeks and in pregnant rats with inhalation exposure to 48 ppm for 11 days. Pulmonary irritation was also present in pregnant rats treated with an oral dose of 500 mg/kg/day for 11 days (Weeks et al. 1979). Effects on the respiratory epithelium were not apparent in the tissue of the lungs, nasal cavity, nasal turbinates, larynx, trachea, or bronchi based on histopathological examination (NTP 1977, 1989 Weeks et al. 1979). Exposure to... 

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