藥物の濃度と作用に關する研究

灌流および小動物環界液に藥物を與えた場合の實驗

抄録

(1) On the assumption that a certain concentration of drugs at the point of action produces a selected effect to organism when the drug in the various concentration streams through the blood vessel, the relation between concentration and the time needed to produce their effects can be expressed by the formula kt=logC/C-C1… (A)
t=the time, C=external concentration of drugs, k=constant different according to the empirical system and C₁=threshold concentration which can be measured directly. The above formula (A) can be replaced by the formula, C_t=at the great part of that time-concentration curve, but C^mt=k… (B) may be considered as the general formula. (2) Observing the effect of drugs on small animals in a certain various concentration of drugs after the absorption of drugs through the surface of their bodies, we can get the above formula (A) or (B) as time-concentration curve. (3) My experimental results showed that the formula (B) had m=1 as the value over a wide range of concentration of drugs and on the other hand the value changed abruptly to become about 0.7 (0.58-0.8) at where concentration was large, but only strophanthin was m=0.26. In the case of perfusing experiment by drugs which seemed to act as protoplasmic poisons, the value of m was 0.65 or 0.7 all over the whole. (4) From the experimental results it may be said that drugs should reach the point of action in organism considerably slower than the rate of uptake by the surface from the external milieu. It can be concluded that in the case of the reversible action of drugs, i. e. in the most cases of drug actions the drugs should produce the certain effect when the certain concentration of drugs have been attained at the point of action mainly by adsorption.