出版社：National Institute of Occupational Safety and Health
摘要：Responses of delta-aminolevulinic acid (ALA) dehydrase activity in erythrocytes to cadmium, mercury and lead ions were investigated in vitro and in vivo. In vitro all of three metals inhibited the purified enzyme activity at the concentra- tion of 10-4M, indicating that the enzyme belongs to the sulfhydryl enzymes. On the other hand, the decrease of the enzyme activity below 40% of the control level was observed only in lead-treated mice, and in cadmium- or mercury-treated mice the transient decrease in the enzyme activity up to 40% of the control level in the initial stage was followed by the increase in the enzyme activity more than the control level in the later stage. It is concluded that both the decrease of the ALA dehydrase activity betow 40% of the control level and the increase in urinary ALA excretion are specific parameters for lead exposure.
