Relationships between the lung mesenchymal cell populations: concurrent elicitation by air and blood ways of the lung reacting cell systems.

Some relationships between the lung reacting cell populations connected to the air and blood ways are investigated by elicitation with proteins in Freund's adjuvant and with SiO2. The agents were intratracheally and respectively intravenously injected into rabbits concomitantly or in different orders and times. The developmental analysis of the alveolar silicotic nodules and of the proteolipidic perivascular ones pointed out the involvement of both reacting cell systems in relation with the administration route, the involvement of local cells only, when the agent is less active and the arrival of blood mononuclears when the agent is more active. A concurrent taking part of the reacting cell systems in the process is demonstrated. The immune phenomena developed by both the used agents also elimine numerous cells from the formation process of nodules, and allow the production of hypersensitive reactions of the immediate and cellular type which influence the integrity and cellularity of formed nodules. The relationships between these two reacting cell systems of the lung appear to be not only quantitative but also qualitative.