Platelet aggregation and increased pulmonary vascular resistance in cats induced by DAS and ADP

In cats the intravenous injection of a substance enriched from stored serum (DAS=depressor active substance) led to an extreme increase in pulmonary vascular resistance (PVR) and at the same time to a marked decrease in platelet count. The maximum increase in PVR was significantly related to the platelet count. The histologic examination of lung tissue—taken at the time of maximum increase in PVR—revealed an extensive microembolism of the terminal pulmonary vessels by platelet aggregates.