An experimental physiological study on plasmin substances in saliva of rabbits.

It was in the year 1893 that DASTRE [1] gave the term fibrinolysis to the phenomenon that a cluster of fibrins in the blood solves itself without the bacterial contamination and regains the character of fluidity in it. Much later, in 1946 MACFARLAN et al. [2] found as plasmin a proteolytic enzyme which is concerned in this phenomenon. Since this time, plasmin and a series of substances related to it are called plasmin substances and till about 1950 these substances had been considered as being involved in shock or allergic complaints through the researches by NOLF [3] and MACFARLAN et al. [4]. In 1952, RATNOFF [5] and STEFANINI [6] among others gave a report that in such clinical instances as a heavy hemorrhage attendant on a surgical operation orpur pura a high degree of plasmin activity is found upon a careful examination of blood. Since 1952 to the present, many researches have been conducted on plasmin substances as having important bearings on hemorrhage and with the discovery of an anti plasmin agent (epsilon amino-caproic acid) by OKAMOTO et al. [7], interest in plasmin substances came to assume an intensified tone. These plasmin substances exist as an inactive state of plasminogen and of proactivator not only in blood and body liquids, but also in such tissues suscestible of bleeding as the prostate, uterus, thyroid gland , suprarenal body, lymphatic gland, etc. At the time of bleeding , the existence of tissue activator is known to gain in force to a considerable degree. Confining our attention to the literature dealing with plasmin substances in the oral area, we learn that ALBRECHTSEN et al. [8] had already discovered the activator ,TAYLOR et al. [9] denied the existence of plasminogen as well as activator in saliva and the present authos and his collaborator [10], on the other hand, established the existence of three plasmin substances : plasmin, activator and proactivator in human saliva by the use of fibrin plate. From the fact that fibrinolytic substance exists in human saliva, OSHIKANE [11] has published a conclusion that as saliva promotes the fibrinolysis, wounds inflicted in the oral cavity tend to be healed quicker as compared with those on the other part of human body. In the First Part of these studies, the authors reported on his findings of plasmin substances in the oral cavity and other related tissues [14]. Here he is concerned with