- Turkish Journal of Medical Sciences
- Vol: 39 Issue: 5
- Reference value for the ALAD enzyme activity ratio in men based on the improvement of each analytica...
Reference value for the ALAD enzyme activity ratio in men based on the improvement of each analytical step of the colorimetric method and the active/non-active lead concept
Authors : Mustafa Gültepe
Pages : 775-781
View : 8 | Download : 5
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :Aim: The ALAD enzyme activity ratio, which is highly sensitive to and specific for lead inhibition, can be used to diagnose lead-exposed individuals, but a reference value for it has not yet been established. Therefore, we aimed to establish a reference value for the ALAD activity ratio by improving each analytical step of the colorimetric method described by Mitchell et al. Materials and methods: Activators, pH, hemolyzing agents, and Ehrlich’s reagent were evaluated to obtain the optimal conditions for the restoration of lead-inhibited ALAD enzyme activity. Results: ZnCl2 and DTT were the preferred activators, the pH of sodium phosphate buffer was adjusted to 6.2, and distilled water was used as a hemolyzing agent. CV for the imprecision of non-activated ALAD, activated ALAD, and the activity ratio was decreased from 5.1%, 3.7%, and 7.1% to 2.6%, 1.9%, and 1.9%, respectively. Linearity improved from 20-fold dilution to 80-fold. Higher activated absorbances were observed at moderately high lead concentrations (12.5-50 µg dL−1). Conclusion: The reference value for the ALAD activity ratio based on 137 healthy men was 0.32-0.64. We think that the activity ratio could be a useful marker for screening lead-exposed individuals. It is also suggested that lead could behave as both an active and non-active metal.Keywords : Key words: ALAD, reference value, activity ratio, active lead