EXPERIMENTAL STUDIES ON THE TOXICITY OF BENZENE HEXACHLORIDE (BHC) AND DICHLORODIPHENYLTRICHLOROETHANE (DDT)I. TOXICITY TESTS OF THE INSECTICIDES FOLLOWING VARIOUS ADMINISTRATIONS TO LABORATORY ANIMALS

摘要

The summary of the above-mentioned experiments are as follows: 1) In the acute toxicity test, as shown in Table 13, the lethal doses in various administrations, though considerable differences can be seen according to the kinds of laboratory animals or their degrees of growth, are the lowest in gamma BHC, next the BHC-mixture and the highest DDT. It is shown that DDT is less toxic than BHC. As for gamma BHC, in the case of intraperitoneal injection, the lethal dose is the least; in subcutaneous injection, peroral administration and percutaneous administration, in that order the lethal doses increase. This proves that in the intraperitoneal injection the absorption is the fastest. Subcutaneous injection and peroral administration are next to it and in percutaneous administration, absorption is the slowest. On the contrary, in the case of DDT, the aspects are a little different. In peroral administration the absorption is the fastest, and the absorption decreases in the following order, i. e., intraperitoneal injection, percutaneous administration and subcutaneous injection. These variations in the lethal doses seem to be due to the irregularities of absorption of each oil solution and the differences of the antidotal action of the liver and the other organs. Moreover, the kind of solvents and the methods of administration may be concerned with the velocity of absorption or with the antidotal action. Comparing the time required to express toxic symptoms in each oil solution, as shown in Table 14, BHC is faster than DDT in cases of intraperitoneal and subcutaneous injections, and DDT is faster than BHC in peroral and percutaneous administrations. In addition, comparing the time required to die in each administration, as shown in Table 14, in gamma BHC intraperitoneal injection requires the least time and decreases in the following order : subcutaneous injection, peroral and percutaneous administrations. In DDT, peroral administration requires the least time and decreases in the following order : intraperitoneal, percutaneous and subcutaneous administrations. The amount of time required to die coincides with the strength of toxicity in the lethal dose of acute toxicity in Table 13. Next to summarized the toxic symptoms in each oil solution, less than the lethal dose of BHC resulted in loss of appetite and excitability were seen, but the growth of animals was not prevented. As for the symptoms caused by a greater than lethal dose, respiration is at first hastened then a calmness could be seen. After several minutes or several hours later, excitability rose to madness, hemorrhages could be seen at nasal passages, around eye-lids and from the vaginal opening of female rats. Tremors were barely noticed, though some died after convulsions. Some survived after the convulsions and were growing naturally. In pregnant rats the toxic symptoms were severe and the lethal dose was lower. On these symptoms, Cameron, Slade, Létard & deSacy, Tareeva recognized almost the same results. In DDT, compared with BHC, the symptoms are revealed remarkably well, that is, tremors easily appeared with less than lethal dose there was a sensitiveness to outer stimuli, especially to sounds. There was also a momentary reaction of jumping and more remarkable tremors were observed when these stimuli came. Some recovered gradually from tremors and showed normal growth afterwards. Others could not take food because of tremors gradually becoming violent, laid down laterally . The limbs became paralyzed and most of them died shortly thereafter. The remarkable loss of weight was possibly caused by this impossibility to take food or loss of appetite. Besides the hemorrhages, which could be seen in the case of BHC poisoning, at nasal part, around eye-lids and from the vaginal opening of female rats, were not entirely observed.