Abstract
Extract
In a previous communication it was reported that a biphasic increase in vascular permeability occurs following intradermal injection of turpentine in the sheep; an early phase seems to be mediated by histamine (Lancaster and Vegad, Citation1967). Later experiments depleting sheep of their stores of histamine by compound 48/80, a histamine liberator, have confirmed the biphasic nature of the increase in vascular permeability in turpentine-induced pleurisy in the, sheep and mediation of the early phase by histamine (Vegad, Citation1971a). Histamine is also released in the sheep in the early phase, of inflammation following thermal injury (Vegad, Citation1971b), and in the cutaneous antigen-antibody reactions (Vegad and Lancaster, Citation1972a). Despite this, however, mediation of the, increased vascular permeability in the delayed phase of the inflammatory reaction, which appears to be the major part of the response, remains uncertain; this is similar to the situation both in the rat (Spector and Willoughby, Citation1965) and in the, guinea-pig (Wilhelm, Citation1965, Citation1968).