[Effects of acetylcholine- and histamine inhalations also of hypoxia on the arterial plasma-histamine concentration (experiments on dogs). III. Communication (author's transl)].

Inhalation of acetylcholine causes increased histamine concentration in the arterial plasma. This increase is smaller than that following allergen inhalation. The increase in Edyn following ACH inhalation may be related to the histamine released to only a very limited extent. Comparison of the effects of histamine inhalation and allergen inhalation on Edyn and plasma histamine concentration leads to the assumption that sensory receptors are located nearer to the surface of the mucosa than that of the mast cells. Hypoxemia is followed by a slight increase in the arterial plasma histamine concentration. The increase in Edyn corresponds to that caused by allergen inhalation although the increase in Edyn and that in the plasma histamine are much smaller.