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Effects of postural alterations on the volume, pressure, and flow rate of air inspired and expired by conscious felines
Author(s) -
Sabol Robert J,
Arshian Milad,
Yates Bill J
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a373-d
Subject(s) - volume (thermodynamics) , volumetric flow rate , flow (mathematics) , medicine , mechanics , thermodynamics , physics
Previous studies have demonstrated that the activities of the diaphragm, abdominal muscles and upper airway muscles including genioglossus are adjusted during postural alterations. Several lines of evidence have suggested that the vestibular system contributes to producing these posturally‐related respiratory muscle responses. However, no previous systematic study has considered the consequences of postural alterations on the movement of air into and out of an animal’s lungs. The goal of the present experiment was to determine the effects of static head‐up tilts of conscious felines on the volume, pressure and flow rate of air during inspiration and expiration. Cats were trained to remain sedentary in the prone position on a tilt table during whole body rotations up to 60° in amplitude; straps were employed to prevent the animal’s position from shifting during testing, and the animal’s head was immobilized by inserting a screw into a bolt mounted on the skull. A facemask secured around the nose and mouth was connected to a Hans‐Rudolph pneumotach system, so that the movement of air during breathing could be quantified. 60° head‐up tilts consistently resulted in a 4–22% reduction in breathing rate and a 4–31% increase in tidal volume. In addition, peak airflow rates during inspiration consistently increased by 9–11%. However, head‐up tilts resulted in increases in peak expiratory flow rates, peak expiratory pressures, and peak inspiratory pressures in some cases, but reductions in these parameters in others. These data demonstrate that head‐up rotations result in felines taking deeper and more prolonged breaths. Subsequent experiments will determine the role of the vestibular system in evoking this adjustment in respiration. Supported by NIH grant R01 DC03732.