WASHINGTON -- Discovery of a way to activate stalled molecular water pumps inside human cells "opens the way" to arresting the course of cystic fibrosis, one of the most common fatal genetic diseases in America, government health officials said yesterday.
With luck, a drug to treat cystic fibrosis based on that discovery could be at the testing stage within a year, said Dr. Michael R. Knowles, one of three University of North Carolina medical school researchers who announced the finding.
The basic defect is the inability of the cells to maintain sufficient water to thin mucus in the lungs, he said.
Dr. Knowles explained that in healthy people, the flow of water in and out of cells is controlled by the movement of electrically charged molecules. Water follows chloride molecules leaving cells and follows sodium molecules into cells.
In people with cystic fibrosis, the cells do not have the ability to initiate the outward flow of chloride molecules or to curtail the inward flow of sodium. Like plumbing with stuck valves, the cells remove water from the mucus and do not replace it. Consequently, the mucus thickens, which promotes bacterial growth and leads to frequent infections and progressive lung damage.
Dr. Knowles and his colleagues have discovered that two compounds that occur naturally in the body trigger the mechanism for taking chloride out and in an earlier discovery, the North Carolina group was able to block the sodium intake.
Together, the two substances could lead to maintenance of normal mucus constituency, said Dr. Knowles and two co-researchers, who announced the discovery in the New England Journal of Medicine.