Tomokuni K, Ichiba M, Hirai Y
Department of Community Health Science, Saga Medical School, Japan.
Arch Toxicol. 1989;63(1):23-8. doi: 10.1007/BF00334629.
The urinary excretion of delta-aminolevulinic acid (ALA) and coproporphyrin (CP) isomers (I and III) was investigated in mice exposed to lead in drinking water (200 and 500 ppm) for 14 or 30 days. Furthermore, the inhibition of pyrimidine 5'-nucleotidase (P5N) and delta-aminolevulinic acid dehydratase (ALAD) was studied in the same mice. In the lead-exposed mice, urinary excretion of ALA was significantly elevated (12-times control), while that of CP remained unchanged. This discrepancy on the urinary excretion may be of interest. The P5N activity in both erythrocytes and bone marrow cells was significantly inhibited by exposure to lead. However, the degree of inhibition was greater in the erythrocytes (45% inhibition) than in the bone marrow cells (25% inhibition). The inhibition of ALAD was much higher in erythrocytes (90% inhibition) than in liver (20-40% inhibition). The increase in erythrocyte protoporphyrin and the decrease in both hemoglobin and hematocrit were not observed in mice exposed to lead under the above conditions.
研究了饮用含铅（200和500 ppm）水14天或30天的小鼠中δ-氨基乙酰丙酸（ALA）和粪卟啉（CP）异构体（I和III）的尿排泄情况。此外，还研究了同一批小鼠中嘧啶5'-核苷酸酶（P5N）和δ-氨基乙酰丙酸脱水酶（ALAD）的抑制情况。在铅暴露小鼠中，ALA的尿排泄显著升高（为对照的12倍），而CP的尿排泄保持不变。这种尿排泄的差异可能值得关注。铅暴露会显著抑制红细胞和骨髓细胞中的P5N活性。然而，红细胞中的抑制程度（45%抑制）大于骨髓细胞（25%抑制）。ALAD在红细胞中的抑制率（90%抑制）远高于肝脏（20 - 40%抑制）。在上述条件下暴露于铅的小鼠中未观察到红细胞原卟啉增加以及血红蛋白和血细胞比容降低的情况。
