It has become apparent recently that pulmonary surfactant phospholipid molecules move between functional compartments within the alveolar subphase of the lung, including extensive recycling of surfactant to the type II pneumocytes. Evidence has been obtained for the existence of a protein in the alveolar subphase that catalyzes the transfer of phospholipids between artificial membranes. The projects outlined in this proposal are directed at determining whether or not this protein is a normal secretory component of type II pneumocytes and whether or not this protein can catalyze the reincorporation of surfactant phospholipids back into the type II pneumocyte for recycling. Type II pneumocytes will be isolated from rat lungs using elastase. The cells in monolayer culture will be stimulated to secrete surfactant and the medium will be examined for phospholipid transfer activity. Other experiments will involve incubation of isolated type II pneumocytes in suspension culture with a purified phospholipid transfer protein from lavage material. Vesicles of various composition will be used as donor membranes and the nature and specificity of the transfer process to the type II pneumocyte determined. An elucidation of the mechanisms controlling the movement of phospholipids between the various functional compartments of the lung is essential to understanding and eventually manipulating the pulmonary surfactant system. A clear understanding of the role of alveolar subphase proteins may be required before a fully functional artificial surfactant can be developed.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Academic Research Enhancement Awards (AREA) (R15)
Project #
1R15HL037232-01
Application #
3439974
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1986-09-30
Project End
1988-03-31
Budget Start
1986-09-30
Budget End
1988-03-31
Support Year
1
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Western Carolina University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Cullowhee
State
NC
Country
United States
Zip Code
28723
Higashimori, K; Gante, J; Holzemann, G et al. (1991) Significance of vascular renin for local generation of angiotensins. Hypertension 17:270-7