Degradation and excretion after tetraethyllead injection and erythrocyte delta-aminolevulinic acid dehydrase activity inhibition in rabbit (author's transl)

Abstract

Rabbits were injected tetraethyllead (Et4Pb) i.v. only once; total lead and triethyllead (Et3Pb) levels in organs were determined 24 hours, and 30, 60, and 90 days later; and the lead clearance rates in the organs were compared with each other. Total lead and Et3Pb outputs in the feces and urine of these rabbits were sequentially determined after the injection. Other rabbits were injected Et3Pb i.v. only once, and Et3Pb and total lead clearances from organs were determined 24 hours and 20 days after the injection. In order to compare the clearances of Et4Pb and inorganic lead from organs, rabbits were injected lead acetate i.v. only once; lead acetate levels in various organs were determined 24 hours and 30 days after the injection; and the in vivo distribution patterns of this compound were compared with the distribution patterns of lead in the aforemetioned animals injected Et4Pb. Furthermore, lead outputs in the feces and urine of these animals were sequentially determined after the injection, to observe the differences in the output patterns between these animals and the aforementioned rabbits injected Et4Pb. 1) The rabbits 24 hours after the i.v. injection of 12 mg/kg of Et4Pb (7.7 mg/kg as lead) gave such a pattern of total lead distribution into various organs that total lead was distributed into the liver>kidney»brain>skeletal muscle>cardiac muscle>spinal cord in the decreasing sequence of level. The total lead levels in the organs showed such a pattern that the level in the liver was 43 times higher, the level in the kidney was 19 times higher, the level in the brain was 4.5 times higher, the level in the skeletal muscle was 4 times higher, the level in the cardiac muscle was 4 times higher, and the level in the spinal cord was 3 times higher than the blood total lead level. The Et3Pb levels in various organs were of such a pattern that the compound was distributed into the liver>kidney»brain>skeletal muscle>cardiac muscle>spinal cord in the decreasing sequence of level; and the Et3Pb levels in the organs showed that the level in the liver was 100 times as high, the level in the kidney was 40 times as high, the level in the brain was 10 times as high, the level in the skeletal muscle was 9 times as high, the level in the cardiac muscle was 8 times as high, and the level in the spinal cord was 5.5 times as high as that in the blood. The Et3Pb/ total lead level ratio was 86% in the liver, 77% in the kidney, 85% in the brain, 79% in the skeletal muscle, 78% in the cardiac muscle, and 37% in the blood. The total lead levels in various organs of rabbits 30 days after the i.v. injection of Et4Pb showed such a pattern that the level in the liver was 1/20; the level in the kidney, 1/50; the level in the brain, 1/40, the level in the skeletal muscle, 1/40; the level in the cardiac muscle, 1/130, and the level in the blood, 1/8, compared with the levels 24 hours after the injection. The Et3Pb/total lead level ratio 30 days after the injection of Et4Pb was 96% in the liver, 6l% in the kidney, 38% in the brain, and 2% in the blood. Sixty days after the injection of Et4Pb, Et3Pb was demonstrated in the liver, kidney and blood, but 90 days after the injection, it was demonstrated in minute amounts only in the liver and kidney. 2) In the rabbits 24 hours after the i.v. jnjection of 6 mg/kg of Et3Pb, total lead was distributed into the liver>kidney»brain>skeletal muscle>spinal cord>cardiac muscle>blood in the decreasing sequence of level. This group showed such Et3Pb/total lead ratios as 100% in the brain, spinal cord and skeletal muscle, 80-90% in the liver and kidney, and 28% in the blood, Twenty days after the injection of Et3Pb, the total lead levels in the organs were decreased in a similar pattern to those in the aforementioned rabbits injected Et4Pb, with the Et3Pb/total lead level ratio being 7l% in the brain, 89% in the liver and 2% in the blood. 3) The rabbits