Activity of Delta-Aminolevulinic Acid Dehydratase in the Peripheral Blood of Male Rats Under Chronic Intake of Lead in Small Doses

The article presents the results of evaluating the activity of delta-aminolevulinic acid dehydratase (δ-ALAD) in the peripheral blood of male rats «Wistar» lines under chronic lead intake at doses of 1.9, 2.3 and 3.9 mcg•kg-1 body weight. Clinically healthy male rats (age 3-4 months) were divided into four groups of 30 heads each. 1 group of animals received the basic ration and served as a control. Rats of groups 2, 3 and 4 (experiment) received of meat 5 gram with different lead content daily for 180 days of the study in addition to the basic ration. Concentration of lead in meat was 0.13; 0.16 and 0.27 mg•kg-1, respectively. Peripheral blood samples were taken under ether anesthesia from five animals from each group on the 30th, 60th, 90th, 120th, 150th and 180th days of intoxication. During the entire study period, appetite (feed intake), reaction to external stimuli, body weight and the functional state of the gastrointestinal tract were taken into account in animals. It was shown that when exposed to lead in small doses, changes in the activity of δ-ALAD in the peripheral blood of experimental animals are nonlinear. In group 2 rats, on the 90th and 120th days of the study, the enzyme activity in the blood significantly increased. On the contrary, inhibition of δ-ALAD activity was observed in animals of group 4. Significant differences in values were noted on the 120th and 150th days of the study. At the same time, the rats of the 3 groups recorded a multidirectional nature of changes in the values of the indicator: on the 30th and 60th days of the study, an increase, and on the 150th day, a decrease. It should be emphasized that inhibition of the activity of δ-ALAD in the peripheral blood of male rats is one of the early signs of poisoning of the body with lead compounds. The results obtained can be used in rationing lead in agricultural products of animal origin and feed for farm animals and poultry, as well as in clarifying the permissible levels of daily intake into the mammalian body.