Kinins in Chronic Inflammation

Abstract

There are several factors which indicate that kinins play a role in inflammatory reactions. Firstly they possess the pharmacological actions which characterise the inflammatory response. For example kinins give rise to changes in the blood vessels and in the extravascular space similar to those which occur during the early stages of inflammation. Blood flow through the inflamed tissue is increased as a result of vasodilatation; fluid containing a high concentration of plasma protein escapes from the vessels into the interstitial space; and the flow of lymph leaving the area and its protein content are both increased. In addition kinins produce pain and although there is tachyphylaxis the pain sensation is like that produced during tissue injury. Finally in higher concentrations kinins cause accumulation of polymorphonuclear leucocytes, although it is difficult to ascertain whether this is a direct action of the peptides or the result of other substances which have escaped from the plasma after the kinins had increased vascular permeability.