Dr Stuart Wilson

During adult life, the lung tissues continually absorb liquid from the airspaces ensuring that the gas exchanging epithelium is covered by only a thin film of liquid that cannot impede the diffusion of gases. However, this capacity to absorb water develops very late in foetal life, appearing only during labour and birth. This has important consequences as it implies that premature babies are, almost invariably, born with immature lungs that cannot adequately absorb water. Such babies' lungs are thus waterlogged, which means that the blood cannot be adequately oxygenated. This is an important and dangerous feature of a clinical condition know as respiratory distress syndrome (RDS), the commonest cause of death amongst newborn and premature infants in the developed world.

Classical studies of foetal lambs showed that the absorption of lung liquid is driven by the active transport of Na ions. This, in turn, is dependent upon specialised proteins, known as Na channels that allow this ion to cross the cell membrane. The importance of these channels to lung liquid clearance was beautifully illustrated by studies of genetically modified mice, in which the genes encoding the channel proteins had been artificially deleted. This caused death from severe RDS within 48 h of birth.

Previous work from the Lung Membrane Transport Group has identified a number of possible factors that may trigger the functional expression of these Na channels around the time of birth. These include circulating hormones such as thyroxin, and the changes in ambient oxygen concentration that occurs as the newborn infant takes its first breaths. Our most recent work has been focussed upon developing methods that will allow us to understand the way in which these factors control expression of Na channel proteins. An important aspect of this project was to develop methods that would allow us to monitor channel activity in single cells that had been isolated from the lungs of foetal rats. The principal underlying these measurements is that, because they are changed, the movement of Na ions into / out of the cell is an event that will carry electrical current. It is thus possible to use electrical methods to monitor the movement of these ions through Na channels.

Publications

Maintained by: H Murphie.

The University of Dundee is a Scottish Registered Charity, No.SC015096

Disclaimer | Privacy

Page last updated: Wednesday 23 April 2008 12:44 PM