Effects of exposure to different manganese compounds on striatal DA and Dopac levels. Striatal slices from male Sprague Dawley rats were collected and incubated for 4 h either in control medium or in medium containing MnCl2 (10, 100, 1000 μM), MnSO4 (10, 100, and 1000 μM), or MnPO4 (1, 10, 100 μM). Tissue DA (Fig. 2a), media DA (Fig. 2b), and media Dopac (Fig. 2c) levels were analyzed by HPLC-ECD and the data was subsequently normalized on a per mg of protein basis and expressed as a percent of vehicle control. *, **, *** Presence and number of asterisks indicate significant differences (P ≤ 0.05).