Bradykinin and Pulmonary Vascular Permeability in Isolated Blood-Perfused Rabbit Lungs

Abstract

Bradykinin causes a marked vasodilatation in most areas of the systemic circulation. In the pulmonary vascular bed of various species, however, bradykinin seems to cause vasoconstriction, as is shown by several investigators (Lecomte and Troquet, 1960; Gersmeyer and Spitzbarth, 1961; Klupp and Konzett, 1963; Hauge et al., 1964). Another important effect of bradykinin in systemic vascular areas is the increase in capillary permeability, which has been demonstrated by various techniques. Kjellmer and Odelram (1965) found that a marked and irreversible edema might develop in skeletal muscle on intravascular administration of bradykinin. We have been interested in the possible effect of intravascularly administered bradykinin on permeability of the small vessels in the lung, since vasoconstriction is the response of some larger pulmonary vessels to this substance. The problem related to such a permeability effect seemed to be of considerable practical, as well as theoretical, interest.