The literature indicates that vasoactive substances released from platelets contribute to the pulmonary pressor response and hypoxemia during pulmonary microembolism. Hence, removal of the platelets or inhibition of their function should reduce these effects. The purpose of this study was, therefore, to investigate the pulmonary effects of experimental embolism with glass beads in dogs rendered thrombocytopenic with platelet antiserum and to compare these effects to the effects in dogs pretreated with sulfinpyrazone (Anturane) or heparin, both substances that affect the function of platelets, probably by inhibiting the release of platelets. In all three groups the pulmonary hypertension was reduced by more than half, and hypoxemia was lessened or abolished. The results of this study indicate the platelets contribute to the effects of pulmonary microembolism and that administration of sulfinpyrazone or heparin reduces the embolism-induced pulmonary hypertension to the same extent as the depletion of platelets. Platelet-inhibiting drugs might therefore be useful prophylactically in human pulmonary microembolism.
Bibliographical noteFunding Information:
We wish to thank Ms. Rosann Glas, Mr. Steve Hofmeister, Mr. Bruce Hookway, Mr. Don Jackson, Ms. Bea Kaplan, Mr. Leonard Latham, Ms. Mary Munroe, and Ms. Eva Toyos for their assistance in this study. We are also grateful to Ms. Susan Konkol for the preparation of the manuscript. Sulfinpyrazone (Anturane) was supplied by CIBA-GEIGY Corp., Summit, NJ.