Bushnell P J, Bowman R E
J Toxicol Environ Health. 1979 Nov;5(6):1015-23. doi: 10.1080/15287397909529810.
Lead acetate in milk was fed daily to infant rhesus monkeys at doses averaging 0 (control), 0.287 (low-Pb), or 0.880 (high-Pb) mg/kgd for the first year of life. Pb concentrations in whole blood (PbB) averaged 4.15, 31.71, and 65.17 microgram/dl for the control, low-Pb, and high-Pb groups, respectively, during the year of treatment and declined toward control levels when Pb dosing was stopped. Behavioral observations during the year of treatment had shown that both experimental groups were retarded in their acquisition of object-cue discrimination reversal learning sets. At 4 yr of age, when PbB levels in all animals were normal, the ability of the same monkeys to acquire a series of 3 spatial-cue reversal learning sets was examined; these data form the basis for this report. In the first problem, the high-Pb group was significantly retarded in acquisition of the original discrimination and of most reversals, and the low-Pb group was retarded on reversal 1 only. These deficits declined in severity across the three problems administered, in a manner similar to that seen in the tests given during the first year of life. These data demonstrate that reversal learning retardation, observed early in life, can recur in postadolescent primates with a history of chronic, low-level Pb intoxication during infancy.
在恒河猴幼猴生命的第一年，每天给它们喂食含醋酸铅的牛奶，剂量平均为0（对照组）、0.287（低铅组）或0.880（高铅组）毫克/千克/天。在治疗期间，对照组、低铅组和高铅组全血铅浓度（PbB）平均分别为4.15、31.71和65.17微克/分升，停止铅给药后，其浓度向对照组水平下降。治疗期间的行为观察表明，两个实验组在获取物体线索辨别反转学习集方面均有延迟。在4岁时，当所有动物的全血铅水平正常时，对同一只猴子获取一系列3个空间线索反转学习集的能力进行了检测；这些数据构成了本报告的基础。在第一个问题中，高铅组在获取原始辨别和大多数反转方面明显延迟，低铅组仅在第一次反转时延迟。在进行的三个问题中，这些缺陷的严重程度逐渐降低，其方式与在生命第一年进行的测试中所见相似。这些数据表明，在生命早期观察到的反转学习延迟，在有婴儿期慢性低水平铅中毒史的青春期后灵长类动物中可能会再次出现。
