Abstract
Thirty-four mongrel dogs were anesthetized with sodium pentobarbital. The inactivation of various vasoactive substances in the lung was investigated by injecting them into the left ventricle (LV) and into the right ventricle (RV) monitoring systemic blood pressure (PSYST) and femoral artery blood flow (QFEM) . The percentage inactivation of various vaso-active substances was calculated from the difference of PSYST and QFEM responses by injecting them into LV and RV.
1) Prostaglandin E2 (PGE2), PGF2α, leukotriene C4 (LTC4), LTD4, acetylcholine and serotonin were inactivated in the lung. The percentage inactivation of these substances was decreased dose-dependently.
2) In canine lungs of pulmonary embolism induced by glass beads injection, the percentage inactivation of PGF2α and acetylcholine was significantly low in comparison with normal canine lungs.
3) In canine lungs with left pulmonary artery trunk clumping, the percentage inactivation of PGE2, PGF2α, LTC4, LTD4, acetylcholine and serotonin was significantly low at the low doses in comparison with normal canine lungs.
Above results suggest that the decrease of pulmonary vascular beds might be the cause of decrease in percentage inactivation of various vasoactive substances following the glass beads-induced pulmonary embolism and the left pulmonary artery trunk clumping.
