The proposed research consists of two groups of studies that deal with Control of Breathing. The first group of studies explores the response of the human respiratory system to changes in its mechanical properties in the conscious state. Specifically, we shall address the following questions: 1) Do normal subjects alter their """"""""inspiratory output"""""""" in the course of progressively increasing resistive and elastic loads, prior to perception of the load? 2) If so, is the response altered in patients with spinal injury? 3) What are the qualitative and quantitative differences in """"""""inspiratory output"""""""" between normal subjects and patients with stable obstructive and restrictive disease? Our investigation of these problems will be greatly facilitated by use of a method, we recently developed, for quantitating """"""""inspiratory output."""""""" The method permits the evaluation of qualitative and quantitative changes in inspiratory activity, throughout the breathing cycle, without being invasive. Our objective is to clarify the mechanisms by which the respiratory system copes with changes in its mechanical properties, and, by extension, the mechanisms of respiratory failure. The second group deals with the basic processes responsible for the sequential alternation between inspiration and expiration and involves detailed examination of the manner with which several inputs are handled by the respiratory oscillator. Special attention will be given to the threshold and integrative properties of the oscillator and to the reversibility of the observed effects. Specifically, we shall test the response to stimulating 3 inspiratory terminating systems namely, sympathetic, intercostal, and laryngeal afferents. In each case inspiratory activity, and the threshold for terminating this activity, will be measured at frequent intervals during and following application of the stimulus. The results should help narrow the possible mechanisms by which respiratory rhythm may originate and clarify the mode of action of different respiratory modulating inputs.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL032030-06
Application #
3343235
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1984-05-01
Project End
1990-04-30
Budget Start
1989-05-01
Budget End
1990-04-30
Support Year
6
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Manitoba
Department
Type
DUNS #
207584707
City
Winnipeg
State
MB
Country
Canada
Zip Code
R3 2N2
Puddy, A; Younes, M (1991) Effect of slowly increasing elastic load on breathing in conscious humans. J Appl Physiol 70:1277-83
Georgopoulos, D; Bshouty, Z; Younes, M et al. (1990) Hypoxic exposure and activation of the afterdischarge mechanism in conscious humans. J Appl Physiol 69:1159-64
Puddy, A; Jung, D; Giesbrecht, G et al. (1990) Mechanism of detection of added respiratory loads. Chest 97:44S
Younes, M; Jung, D; Puddy, A et al. (1990) Role of the chest wall in detection of added elastic loads. J Appl Physiol 68:2241-5
Younes, M; Sanii, R (1989) Effect of phase shifts in pressure-flow relationship on response to inspiratory resistance. J Appl Physiol 67:699-706
Gallagher, C G; Sanii, R; Younes, M (1989) Response of normal subjects to inspiratory resistive unloading. J Appl Physiol 66:1113-9
O'Donnell, D E; Sanii, R; Younes, M (1988) External mechanical loading in conscious humans: role of upper airway mechanoreceptors. J Appl Physiol 65:541-8
Sanii, R; Younes, M (1988) Steady-state response of normal subjects to an inspiratory sinusoidal pressure load. J Appl Physiol 64:511-20
Poon, C S; Younes, M; Gallagher, C G (1987) Effects of expiratory resistive load on respiratory motor output in conscious humans. J Appl Physiol 63:1837-45
Gallagher, C G; Younes, M (1987) Closing volume after inspiratory resistive loading to fatigue. Respir Physiol 68:137-44

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