Experiments on rabbits showed that, in the course of a febrile reaction, alterations in the activities of the kallikrein-kinin, proteolytic, and antiproteolytic systems of the lymph and blood are of a systemic nature, i.e., they occur in all components of humoral transport, attesting to the close interrelationship and unity of these systems in body fluids. Depending on the duration of the febrile reaction, the time course of these systems' components was characterized by phasic increases and decreases in their activity.Key Words: kallikrein-kinin system; lymph; febrile reaction Given the constancy of transcapillary exchange among components of the kallikrein-kinin system (blood -tissue fluid [and cellular elements of the reticuloendothelial system of internal organs] lymph -blood), alterations in its activity during a febrile response should be expected to affect not only the blood but the lymph as well. The resorptive and transporting functions of the lymphatic system may in turn mediate alterations in levels of individual components of the kalli&rein-kinin (KK) system in the blood. On the other hand, there is evidence that the kin_in system plays an important role in the central mechanisms of febrile reactions [4]. In our view, a better insight into the involvement of kinins in febrile reactions of various duration can be gained by undertaking a comparative analysis of alterations that occur during such a reaction in components of the KK, proteolytic, and antiproteolytic systems of the lymph (drained from various body areas) and of the peripheral blood.
MATERIALS AND METHODSFor the study, 76 Chinchilla rabbits weighing 2.5 to 4.2 kg were used. A febrile reaction was pro- duced by intravenous injection of a lipopolysaccharide pyrogen (Pyrogenal) as described previously [8]. Lymph was collected from the thoracic lymphatic duct, the postnodal portion of the hepatic lymphatic duct, and the intestinal lymphatic trunk; blood was taken from the femoral vein. At different times during febrile reactions of varying length, lymph and blood samples were assayed for kininogen [9], prekallikrein, fast-and slow-reacting kallikrein inhibitors (FKI, SKI) [7], a-2-macroglobulin (a-2-MG) [2], and a-l-inhibitor of proteinases (a-l-PI) [13]. Lymph and blood were collected under conditions preventing spontaneous production and degradation of kinins. As controls, rabbits injected with apyrogenic physiological saline were used. Euthanasia after the tests was performed with a lethal dose of a narcotic substance.
RESULTSAs can be seen in Table 1, the lymph samples contained all KK system components required for the formation and inactivation of kinins. Since kinins are normally incapable of penetrating through the vessel wall in an active state [16], their pres-