抄録
In the present study. we examined the difference in hemodynamic responses between groups of canine lung lobes which received latex particles of different sizes (50μm and 300μm in diameter). We also assayed prostaglandin I2 (PGI2) and thromboxane A2 in the effluent blood of the lobes. Reversible pressor response was clear in embolization by 50μm particles whereas it was not in that by 300μm. No difference in PGI2 between two embolizations was seen. We conclude that a local contractile mechanism exists in the pulmonary arterial wall of about 50 pm in diameter whereas participation of the same mechanism is mininal in 300μm, and that this difference cannot be explained from the change in PGI2.
