Shih T M, Hanin I
Psychopharmacology (Berl). 1978 Jul 19;58(3):263-9. doi: 10.1007/BF00427389.
Rats were exposed to lead acetate from birth, and were killed at the age of 44--51 days for analysis of levels and turnover rates of acetylcholine (ACh). Steady-state levels of ACh were not altered in midbrain, cortex, hippocampus, or striatum of lead-exposed rats. Similarly, no changes in choline (Ch) concentrations were found in cortex, hippocampus, or striatum. In the midbrain, however, a 30% reduction in Ch levels was observed. Changes in specific activity of Ch and ACh were measured as a function of time in selected brain areas of rats infused with a radio-labeled precursor of Ch. Specific activities of ACh were not altered. Ch specific activities were, however, significantly elevated in all brain areas examined, as compared with age-matched control rats. The in vivo ACh turnover rate in cortex, hippocampus, and striatum was diminished by 35%, 54%, 51%, and 33%, respectively. These findings provide direct evidence for an inhibitory effect of lead exposure from birth on central cholinergic function in vivo. Since a significant reduction of body weight was found in those animals treated with lead acetate, the alteration of central cholinergic function may partially be attributed to malnutrition observed in the lead-exposed animals.
大鼠从出生起就接触醋酸铅，在44至51日龄时处死，用于分析乙酰胆碱（ACh）的水平和周转率。接触铅的大鼠中脑、皮层、海马体或纹状体中的ACh稳态水平未发生改变。同样，在皮层、海马体或纹状体中未发现胆碱（Ch）浓度有变化。然而，在中脑中观察到Ch水平降低了30%。在注入放射性标记的Ch前体的大鼠的选定脑区中，测量Ch和ACh的比活性随时间的变化。ACh的比活性未改变。然而，与年龄匹配的对照大鼠相比，在所检查的所有脑区中，Ch的比活性均显著升高。皮层、海马体和纹状体中的体内ACh周转率分别降低了35%、54%、51%和33%。这些发现为出生后接触铅对体内中枢胆碱能功能的抑制作用提供了直接证据。由于在用醋酸铅处理的那些动物中发现体重显著减轻，中枢胆碱能功能的改变可能部分归因于接触铅的动物中观察到的营养不良。
