ABSTRACT
In the previous report, we concluded that chances are very slim for Salithion and Sumithion to concentrate in rabbits as these organophosphorous compounds are excreted quickly. This conclusion was inferentially drawn from the results of measurements of concentration of Salithion and Sumithion residues in the blood after experimental exposures of rabbits to the pesticides.<BR>In the present report, we will discuss the same toxicological problem based on our findings in a series of experiments using rabbits with hepatic disturbances induced by carbon tetrachloride (CCl<SUB>4</SUB>).<BR>Rabbits were divided into three groups. One consists of rabbits having light hepatic disorder. They were subcutaneously injected with 0.1ml/kg of 20% CCl4 olive oil for three days consecutively. Under the second group come rabbits with moderate liver disturbance caused by the injection of 0.3 ml/kg of 20% CCl<SUB>4</SUB> olive oil. The injection was also made for three days. The remaining group is the control group.<BR>These rabbits were administered orally with 5mg/kg and 20mg/kg of Smithion for three days running.<BR>The examination covered (1) Sumithion residue level in the blood, (2) PNMC level in urine, (3) hepatic function (ChE, GOT, GPT, BSP, Al-P, BUN), (4) urinalysis and (5) histopathological examination of the liver and the kidney. The results of these tests were studied in comparison with those of the control group.<BR>The following is a summary of our conclusion:<BR>1) In the control group, Sumithion residues in the blood disappeared quickly, and could not be detected 72 hours after administration.<BR>2) As far as the disappearance of Sumithion and the excretion of PNMC are concerned, there was no significant difference between the control and the light and moderate liver disturbance groups of rabbits.<BR>3) In the rabbits with CCl<SUB>4</SUB>-induced liver disturbances, it was noted that the administration of Sumithion impeded serum and red-cell ChE activities to a remarkable extent, and delayed the recovery of the liver function.<BR>4) However, the liver disturbance did not deteriorate. The histological observation of the liver and the kidney did not reveal any abnormality due to the administration of Sumithion, either.