Extrapulmonary airways

Extrapulmonary airways All airways not involved in gas exchange. These... 

This complex circulation system has been proposed to be important for distribution of soluble components of partieles deposited in the eonducting airways (72 Fig. 6). Particles and drugs deposited in the extrapulmonary airways are absorbed into the bronchial circulation, are drained into the right atrium, and are then delivered back to the lung by the pulmonary eirculation, diluted in venous blood coming from the systemic circulation. Drugs can possibly also reach the... 

Plopper CG, Halsebo JE, 8onstegard K8, Nettesheim P. Distribution of nonciliated bronchiolar epithelial (Clara) cells in intra- and extrapulmonary airways of the rabbit. Exp Lung Res 1983 5 79-98. 

Dixon AK, Gubitz AK, Sirinathsinghji DJ, Richardson PJ, Freeman TC (1996) Tissue distribution of adenosine receptor mRNAs in the rat. Br J Pharmacol 118(6) 1461—1468 Douillet CD, Robinson WP 3rd, Zarzaur BL, Lazarowski ER, Boucher RC, Rich PB (2005) Mechanical ventilation alters airway nucleotides and purinoceptors in lung and extrapulmonary organs. Am J Respir Cell Mol Biol 32(l) 52-58... 

Total lung dose Extrapulmonary delivery Distribution within the airways Total systemic exposure... 

The bronchial arteries supply the trachea, pulmonary airways (both intra- and extrapulmonary), regional lymph nodes, (visceral) pleura, esophagus, and vasa vasorum of aorta and pulmonary artery and vein. 

Burges and Blackburn (1972) found that salbutamol selectively activated rat lung adenylate cyclase at concentrations that had no effect on the rat heart enzyme. Nebulized salbutamol can be as effective as that given intravenously (Lawford et al. 1978) but has the added advantage of fewer metabolic and symptomatic side-effects. The S isomer of salbutamol had no activity at extrapulmonary P2-adrenoceptors in man (Lipworth et al. 1997). The R isomer demonstrates approximately equivalent activity to racemic salbutamol when compared on a 1 2 microgram ratio. This suggests that the R isomer may offer possible therapeutic advantages over racemic salbutamol in view of less adverse airway effects with comparable systemic adverse effects. 

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