REPLY FROM DRS. BROWN, PEARSE, PYRGOS, LIU, TOGIAS, AND PERMUTT

Abstract

LETTERS TO THE EDITORREPLY FROM DRS. BROWN, PEARSE, PYRGOS, LIU, TOGIAS, AND PERMUTTRobert H. Brown, David B. Pearse, George Pyrgos, Mark C. Liu, Alkis Togias, and Solbert PermuttRobert H. Brown, David B. Pearse, George Pyrgos, Mark C. Liu, Alkis Togias, and Solbert PermuttPublished Online:01 Dec 2006https://doi.org/10.1152/japplphysiol.00868.2006This is the final version - click for previous versionMoreSectionsPDF (24 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat To the Editor: We accept the inference of Professor Stănescu (2), an authority on the measurement of pleythysmographic lung volumes, that the frequencies used by us for the measurements (1) were in a range where they could have been overestimated. We do not believe, however, that such an overestimation of lung volumes would have had any significance in invalidating our conclusions concerning the structural basis of airways hyperresponsiveness. The key factor that eliminates from consideration the possible role of the Stănescu artifact is the necessity that the Stănescu artifact would cause equal overestimations of functional residual capacity (FRC) and residual volume (RV), as pointed out by Professor Stănescu in his letter. Our conclusions concerning airways hyperresponsiveness are dependent on the magnitude of the difference in the change in the FRC and total lung capacity (TLC) in relation to the change in the RV, and that difference would not have been affected by panting frequency. When the increase in FRC or TLC was small in relation to the increase in RV, hyperresponsiveness was present; when the increase in FRC or TLC was large in relation to the increase in RV (equal or even greater), the hyperresponsiveness was attenuated or even absent. We quantified the relationship between the change in FRC relative to the change in RV by the FRCratio, defined by Eq. 2 in our paper, with the results of the analysis of the FRCratio on the structural basis of airways hyperresponsiveness presented in Tables 3 and 4 of our paper (1). We doubt that Professor Stănescu could account for how the Stănescu artifact could possibly be a determinant of the FRCratio.As to the second point, we do not believe that any position-dependent effects on the measurements could have resulted in the specific relationships we observed between the FRCratio and airway structure as outlined above.REFERENCES1 Brown RH, Pearse DB, Pyrgos G, Liu MC, Togias A, and Permutt S. The structural basis of airways hyperresponsiveness in asthma. J Appl Physiol 101: 30–39, 2006.Link | ISI | Google Scholar2 Stănescu DC. Overestimation of lung volume. J Appl Physiol 101: 1812, 2006.Link | ISI | Google Scholar Download PDF Previous Back to Top Next FiguresReferencesRelatedInformationCited ByLast Word on Viewpoint “The role of the large airways on smooth muscle contraction in asthma”Solbert Permutt1 October 2007 | Journal of Applied Physiology, Vol. 103, No. 4 More from this issue > Volume 101Issue 6December 2006Pages 1813-1813 Copyright & PermissionsCopyright © 2006 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00868.2006History Published online 1 December 2006 Published in print 1 December 2006 Metrics