剔出蟇心臓の長時間灌流の方法に關する實驗

抄録

A new method of perfusion for simultaneous registration of the electro and mechanograms (EG and MG) of the auricular and ventricular activities of an isolated heart of toad has been devised by the author. The most important feature of this method of perfusing the heart suspended in fluid is the combination of two vessels, the one, the vessel for fixing the heart, and the other, the vessel for supplying the perfusion fluids. This combination has proved to be satisfactory for taking more than several hours' records of the auricular and ventricular activities. The septum in the vessel for heart is available to hold the heart in fluid by the auriculo-ventricular region, and, at the same time, to prevent the fluids in both sections for short-circuiting electrically. For MG, the two levers are connected to the auricle and the ventricle respectively. EG is obtained by a pair of non-polarisable electrodes immersed in the fluid in each section. The septum is essential for registering separately the auricular and ventricular activities on the mechanical record as well as the electrical.
Many trials showed that the Mariotte bottle connected directly to the heart for perfusion was not suitable for switching the one fluid to the other without disturbances. The author tried to diminish such undesirable influences by leaving the fluids' surface open to atmosphere, and constructed the vessel for perfusion in two sections, symmetrical in all details and partitioned by a septum having a special cock built in ; the volume of perfusion could be regulated by the difference in height between the two vessels ; the volume of outflow from aorta was also measurable. The graphic records and the volume of perfusion show that there was no noticeable effect of the exchange of perfusion fluids. From this fact, the experimental results such as (1) the distance between and the height and width of the auricular and ventricular waves in MG, (2) P-P, PQ, QRS, QT in EG, and (3) the minute volume of perfusion are all available as the criteria for ascertaining the nature of influences upon the heart.
The graphic records and the minute volume of outflow observed for several hours or even longer by this method can be divided into three periods. In the initial and the last periods, the above mentioned criteria are easily variable even within 10 minutes, while in the middle period, these are more stable and remain almost constant. This period of stationary state usually begins 100 to 130 minutes after the commencement of perfusion, and lasts for 120 to 240 minutes or even longer. As the initial symptoms of the last period, a deviation of EG from the standard state and a decrease in the minute volume of perfusion are more frequently encountered-than changes in MG. The middle period prior to the appearance of such failing signs can be regarded as a state of equilibrium.
The author describes typical changes of the graphic records which occurred when the fluid in the vessel for heart was stirred up, the surface of the heart was touched by the tip of a needle, and the heart was injured by a pair of scissors. He then presents several types of graphic records which were encountered frequently in the course of perfusion, and some examples indicating the superiority of electrography over the mechanography in several respects as a method of recording the activities of an isolated heart.
Using quinidine in various concentrations, he observed its action upon a heart in the middle period of perfusion, and found that even after several repetitions of this kind of test on the same heart, the state of equilibrium with perfect reversibility was well maintained during this period. [Cf. original (japanese) p. 91.]