Abstract

1. The intravenous administration of alloxan, ANTU, iodoacetamide and oxophenarsine produces an increase in pulmonary arterial pressure due to increased resistance in the pulmonary vascular bed. Tachyphylaxis occurs on repeated injections of ANTU, iodoacetamide and oxophenarsine.

2. The increased pressure in the pulmonary vascular bed plays no obvious oontributory role in the production of edema by these compounds, but it is suggested that both effects may result from capillary damage.

3. The rise in pulmonary arterial pressure produced by the continuous infusion of alloxan is inhibited by 1-thiosorbitol and 2,3-dimercaptopropanol.