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C Inflam.matian alt'erslwng cell metabolism. Detailed biochemical studies of what happens in the lungs of mill' work- ers exposed to cotton dust could lead to much earlier detection of lung, damage caused by any of a broad range of irritants, including those found in cigarette smoke. Wil- liam F. Willoughby, associate pro- fessor of pathology and associate professor of' environmental health sciences at Johns Hopkins Univer- sity school of' medicine, Baltimore, has foundl a change in the metabo- lism of a particular type of lung cell-alveolar macrophages-in the. presence of even low levels of' lung inflammation. This metabolic change "makes it' theoretically possible to detect' ac- tive, low-level pulmonary inflam- mation, such as is presumed to bee associated with the development off chronic lung disease in man,"'• Willoughby says. Willoughby, along with postdoc- toral researcher Frank Gerberick, has found that in, the lung, alveolar mac- rophages lose their ability to pro- TKil'loughby': Losfab,iliE,yV reacquired C duce reactive oxygen metabollites such as superoxide anion in response to environmentaf agents. However, if the lung is inflamed, the mac- rophages reacquire this ability with- in about' 48' hours. This change is mediat'ed'i by a 3'0,000!- to 50,000- dalton serumi protein; it requires protein synthesi's by the macro- phage; and it is associated with the generation of a membrane-boundl enzyme that reduces molecular oxy- gen to superoxide anion. The pas- sage of serum proteins into the lungs' air spaces is known to be associated with pulmonary inflam- mation, Willoughby says, and this event is presumably responsible for the change ini the macrophage's biochemistry. Macrophages produce reactive oxygen intermediates as a way to fight bacterial infections, Willough- by explains, His study, which was fundedl by Cotton Inc. and the N'a= tionall Institutes of Health, finds thatt the body, and the lungs in particu- lar, are normally protected from the tissue damage such intermediates can cause even after activating sub- stances have been inhaled from the environment . However, under, ap- propriate circumstances, such as when fightang,bacterial pneumonia, macrophages can quickly regain the ability to produce the reactivee substances. Probably the most important find- ing of the study, however, is that it _ should be possible to assess wheth- er a lung, is inflamed, even at a very low level. The idea is to remove macrophages from air passages and to determine in the laboratoryr whether they are prod'ucing, reac- tive oxygen intermediates.. Low levels of' lung damage or in- flarnmation, such as that sometiimes, associated with cigarette sznoking, !' is not easy to diagnose, Willoughby says. Neither are the early stages of' lung disease in cotton workers and' others for which lung damage is an occupational hazard, such as coal miners and asbestos workers. These conditions usually go undetected until'pul'monaryfunction startstod+ecrease. The technique could bee particularly useful in identifying,in- diividualls~ with the greatest risk of developing chronic lung disease be+ fore they' develop irreversible lung injury, he suggests. p P t,