Cystic fibrosis viscoelasticity

R. P. TaaddewicE, S. Shak, and M. King. Effects of ihDNafie on cystic fibrosis sputum viscoelasticity in vitro. /Wiitc Pulnwnoi. StippI PJt251 (1993). 

Figure 7 Effects of variants of rhDNase I on the compaction of sputum from cystic fibrosis patients. The percent compaction of the sputum (mean SEM), which correlates with sputum viscoelasticity, is plotted versus the variant concentration wild type ( ) active site variants Hisl34Ala (A) and His252Ala ( ) and actin-resistant variants Asp53Arg ( ), Tyr65Ala ( ), Tyr65Arg (A), and Val67Lys (Y). (From Ref. 44.)...

Domase alfa is a mncolytic agent that cleaves DNA released by neutrophils that are mobilized to respiratory tract in response to infection, redncing viscoelasticity of pnrnlent Inng secretions, increasing airflow, and decreasing risk of infection. It is nsed in the treatment of cystic fibrosis. 

Water can bind to mucous glycoprotein (MGP) macromolecules and influence viscosity. Viscosity can be increased by dehydration of the mucus, as can adhesion of mucus-epithelium. In purulent sputum, the correlation between viscosity and dry weight of solids is poor and may explain why mucous glycoprotein content is a poor index of viscoelasticity in chronic bronchitis, bronchiectasis, and cystic fibrosis. Mucus s viscoelasticity increases with acidic pH (3), causing reduced mucociliary clearance. Its viscoelasticity is also dependent on the content of low molecular weight electrolytes. These properties reflect the polyelectrolyte nature of mucins (4-6). 

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