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Mathematical modeling of static hysteresis during inflation deflation cycles in normal and tween-rinsed excised rat lungs.

Authors
Franz-GN; Cheng-W; Frazer-DG
Source
FASEB J 1996 Mar; 10(3):A359
NIOSHTIC No.
20034881
Abstract
Static lung volume-pressure hysteresis can, at least in part, be explained by (I) the opening (recruitment) of closed lung units during inflation from low end-expiratory pressures, (2) the subsequent uniform expansion of open lung units during continued inflation, (3) uniform contraction of open lung units with deflation, and (4) closing (derecruitment) of open lung units with continued deflation to low end-expiratory pressures. (See Frazer et al., Respiration Physiol. 43: 237:246, 1981 and 61: 277-288, 1985.) The model assumes that closing (derecruitment) of open lung units during deflation occurs over a range of normally distributed positive end-expiratory pressures and that opening (recruitment) of closed lung units during inflation occurs at much higher "opening" pressures which are also normally distributed. Excised Tween-rinsed rat lungs exhibit less static hysteresis during a maximal inflation/deflation' cycle than do untreated lungs. For partial deflations from the maximally inflated state, however, tween-rinsed rat lungs exhibit substantial hysteresis for end-expiratory pressures which produce little hysteresis in untreated lungs. Our recruitment/derecruitment model still fits this phenomenon if rinsing with Tween shifts the mean of the distribution of closing pressures by about + 10 cm H2O.
Keywords
Laboratory-animals; Laboratory-testing; Inhalation-studies; Breathing; Pulmonary-system-disorders; Lung-irritants; Mathematical-models
CODEN
FAJOEC
Publication Date
19960308
Document Type
Abstract; Conference/Symposia Proceedings
Fiscal Year
1996
NTIS Accession No.
NTIS Price
Issue of Publication
3
ISSN
0892-6638
NIOSH Division
DRDS
Source Name
The FASEB Journal
State
WV
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