Use of radioisotopes in quantitative studies of lung metabolism.

Quantitatively accurate studies of macromolecule and lipid synthesis in lung and other tissues by using radioactive substrates require detailed knowledge of the specific radioactivity of the appropriate pool of precursor molecules serving the synthetic pathway. A brief summary is provided of how considerations of precursor availability, metabolism, and compartmentation, as well as product remodeling, may affect the accuracy with which rates of protein, DNA, RNA, and lipid synthesis can be measured. Where possible, the application of this material to studies of lung metabolism is discussed, along with approaches that may minimize experimental uncertainties.