[Activities of pulmonary phospholipases of fetal rats. Variations during development].

Turnover of adult rat lung phospholipids implies intervention of phospholipases. This work clearly demonstrates: There is in fetal or adult rat lung an inactive form of phospholipase that is convertible to an active form by the action of lysed platelets. An increase of both active and inactive forms of the fetal enzyme with gestational age. The fact that an important part of these activities, at the time of birth, are in the inactive form implies a control mechanism affecting levels of each form of lung phospholipases. These data are discussed in relation to the possible role of the lung phospholipases in Respiratory Distress Syndrome.