Relationship between hematopoietic parameters and behavioral measures in lead-exposed rats.
The effects of low level lead (Pb) exposure on learning tasks in developing rats were investigated and the results correlated with individual hematopoietic indices. Pups received exposure via the dams milk; dams were exposed to either 0-, 545-, or 1090-ppm Pb during the lactation period. At Day 30 of age, half of the high Pb group was placed on distilled water; the remaining groups continued on the same exposure regimens as their dams. On Days 20, 30, and 90, blood samples for all rats were obtained via cardiac puncture. Each sample was analyzed for Pb concentration, free erythrocyte protoporphyrin (FEPs), hematocrit, and hemoglobin. Beginning at Day 90, all rats were tested on a battery of tasks designed to investigate the following questions: (1) to what degree lead exposure interferes with reversal learning; (2) whether changing of task requirements adversely affects acquisition of a new task; (3) to what extent task difficulty contributes to lead-induced deficits; and (4) whether lead exposure affects the capacity to retain information over short or long periods of time. The actual testing paradigms included spatial discrimination with reversal, visual discrimination with reversal, and visual discrimination task with delay. No significant differences were observed among any of the groups on any of the tasks. Correlation of individual learning scores with individual measures of hematopoietic function also failed to reach significance. These findings indicate that at low exposure levels, lead has little appreciable effect on learning and memory function as measured by these tasks.
D000818:Animals; D004192:Discrimination, Psychological / Q000187:drug effects; D006128:Growth / Q000187:drug effects; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D007854:Lead / Q000097:blood; D007855:Lead Poisoning / Q000097:blood* / Q000523:psychology; D007859:Learning Disabilities / Q000139:chemically induced*; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced; D051381:Rats; D012153:Retention, Psychology / Q000187:drug effects; D013028:Space Perception / Q000187:drug effects; D014796:Visual Perception / Q000187:drug effects
D007854:Lead