Determinants of Circulating Surfactant Protein Levels in Health and Disease [ 2000 - 2002 ]

Research Grant

Researchers: Ian Doyle (Principal investigator)

Brief description The lung allows the oxygenation of blood and clearance of carbon dioxide. To achieve this a large surface area (50-100 m2) interfaces with a complex microcirculation across a 0.1-0.2 ?m barrier - the alveolocapillary membrane. The alveolocapillary membrane is damaged under a variety of circumstances, of varying severity. Whereas severe impairment results in respiratory failure, often there is no clear delineation between OacceptableO and OpathologicalO changes. Therefore, we have coined the term Olung healthO to encompass the broad spectrum. Generally speaking, lung health can be compromised by lifestyle or disease. Whereas lifestyle changes are typically progressive and chronic, those associated with disease tend to be severe and acute. Monitoring lung health clearly has important implications in terms of occupational health and lifestyle issues, including smoking. The need for a marker of lung permeability is also regarded as the Oholy grailO in the intensive care setting. Currently, there is no way of doing so. The alveolus is lined with a liquid layer into which is secreted a complex mixture of lipids and specific proteins known as alveolar surfactant. Surfactant reduces the work of breathing. Recently, we fortuitously discovered that surfactant proteins leak into the circulation and that changes in their levels are a sensitive and early generic index of the lung?s integrity. We discovered that lung damage from conditions as diverse as smoking to the acute respiratory distress syndrome elevate circulating surfactant proteins levels. To refine our discovery we aim to: Improve the techniques used to measure the proteins Study the rate at which they enter and clear the circulation Study the influence of storage, gender, age, circadian rhythm, and smoking on the levels Study the levels in acute lung injury and in radiotherapy and cytotoxic drug treatment where the ability to monitor lung damage has immediate benefit for the patients.

Funding Amount $AUD 276,221.23

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant