Alveolar macrophagic reactions. III. Stereotyped development of alveolar responses to intratracheally administered...

Kinetics of alveolar macrophagic reactions was quantitatively studied at the endoalveolar and parietoalveolar levels after challenge by a single intratracheal administration of several agents, such as mineral dusts, antigenic particles, hormones and drugs. The follow up of all the induced alveolar reactions evidenced their basic character and their stereotyped development irrespective of the challenge. From among the tried substances, heparin and euphylline were chosen for the following experiment due to their stimulatory effects towards the alveolar macrophagic reactions in which they seem to act like chemical mediators. Rabbits with alveolar macrophagic reactions induced by 3 intratracheal injections of aluminum silicate were daily treated with heparin or euphylline: the stimulatory effects of the added drugs obviously contributed to the promotion and prolongation of the increased macrophagic reactions both at the endoalveolar and parietoalveolar levels. The phases of these stereotyped alveolar macrophagic reactions and the involvement of circulation monocytes and of mesenchymal interstitial cells are discussed considering the alveolus as a whole.