Biomaterials and Biomedical Engineering Volume 2, Number 4, December 2015 , pages 225-235 DOI: https://doi.org/10.12989/bme.2015.2.4.225 |
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Combination of isoproterenol and length oscillations in relaxing porcine airway smooth muscles |
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Ahmed M. Al-Jumaily, Meha Mathur and Simeon Cairns
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Abstract | ||
Treatments for asthma are largely pharmaceutical, with some therapies also utilising alternative breathing techniques. The objective of both medical and alternative methods is to relax contracted airway smooth muscle (ASM). In normal subjects, tidal breathing- and deep inspiration-oscillations are believed to have a bronchodilatory effect. Similarly, application of length oscillations to isolated, contracted ASM also elicits muscle relaxation. As a means of investigating more-effective alternative treatment methods for contracted airways, we analyse the combined effects of bronchodilators and length oscillations on isolated, contracted ASM. The contractile state of the muscle tissue prior to treatment is of primary interest. Thereafter, the effect of applying a combination of small superimposed length oscillations with tidal breathing-like oscillations to ASM is studied alone and in combination with a common bronchodilator, isoproterenol (ISO). This work suggests that relaxation of isolated, contracted ASM following application of combined oscillations and ISO is larger than treatments of either combined oscillations or ISO alone. Further, the observed oscillation-associated relaxation is found to be amplitude- rather than frequency- dependent. This study gives additional insight into the role of oscillations and bronchodilators on contracted airways. | ||
Key Words | ||
isoproterenol; length oscillations; airway smooth muscle; porcine | ||
Address | ||
Institute of Biomedical Technologies, Auckland University of Technology, Auckland, New Zealand | ||