The long-term objective of this application is to elucidate the roles of pulmonary afferents in cardiopulmonary diseases. Hyperpnea, tachypnea and dyspnea are common symptoms and signs of cardiopulmonary patients. Those patients often hyperventilate, which is detrimental to their existing disease. There are several types of nerve endings in the lung, which provide the respiratory center with information about mechanical and chemical changes. However, what roles these nerve endings play are still not fully understood. Recently, a vagally mediated 'excitatory lung reflex' is described. Initiation of the reflex may be a key step for the hyperpnea, tachypnea as well as dyspnea during cardiopulmonary diseases. Our preliminary data indicate that the receptor endings for the reflex are located in the small airways.
The specific aims of this project are to identify the structure, mechanical and chemical properties of the responsible endings and to identify their afferent pathways. Phrenic nerve activity and intraluminal pressure in the trachea will be recorded for assessing respiration. The activity in the sensory endings will be recorded to quantify the afferent response. Using neurological and pharmacological methodology to stimulate or block nerve traffic, the reflex effects will be assessed, the reflex pathway will be established and the mechanisms for activation of the receptors will be explored. These physiological results will be confirmed by morphological studies with the techniques such as, neural tracing and histochemistry. The information gained will improve our understanding of neural control of breathing, leading to better clinical management of pulmonary problems.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL058727-05A1
Application #
6576813
Study Section
Special Emphasis Panel (ZRG1-SSS-3 (03))
Program Officer
Twery, Michael
Project Start
1998-07-10
Project End
2007-05-31
Budget Start
2003-08-01
Budget End
2004-05-31
Support Year
5
Fiscal Year
2003
Total Cost
$337,400
Indirect Cost
Name
University of Louisville
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
057588857
City
Louisville
State
KY
Country
United States
Zip Code
40292
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