[Vaso-active substances and pulmonary circulation].

This study reveals the main vaso-active substances which pass through the lung, by studying in each case the extra-pulmonary of pulmonary origin, the effects of the lung on these substances: capture, discharge, transformation, and the effects of these substances on the lung. Eight groups of substances are studied: mediators of the sympatho-adrenergic system, substances interfering with adrenergic agents, acetyl-choline, serotonin, angiotensin, histamine, kinins, and prostaglandins. The lung behaves either as a neutral organ, or a filtering organ, or a filtering organ, or a secreting organ for these substances. In this way it strangely resembles the kidney. The pulmonary circulation is not completely comprised of simple reaction. It is capable of internal adjustement and redistribution under the effect of these substances. Pulmonary edema probably will always remain difficult to their mechanism of production, in so far as can be estimated from the multitude of substances. It is still rather a delicate matter to distinguish between edema-generating phenomena and phenomena which are secondary to the edema itself.