Acetaminophen toxicity in vivo. A.

<p>Brain cortex tissue slices (5 µM thick) from vehicle (V; H₂O:PEG, 1∶1), AAP (250 mg/Kg i.p.) and AAP (500 mg/Kg i.p) injected animals obtained 24 h post-injection, were double-stained with Dapi to identify nuclei, apoptotic neurons were labelled using TUNEL as indicated in Material and Methods. An overlay of both signals (Ovl) is also presented. Arrows indicate cells showing an overlay of TUNEL and Dapi signals. The figure shows a representative experiment that was repeated 3 times with similar results. <b>B.</b> Quantification of damaged neurons. Data represent the percentage of TUNEL positive cells related to total Dapi stained cells. For quantification, a total of 12 image fields from 2 different animals were used for each condition. The average number of cells per field was 79.1±2.8 (mean ± SEM). For each field, the percentage of TUNEL positive neurons was determined. The total number of neurons (100% of the y axis) counted for each experimental condition was: 990 for vehicle; 1050 for AAP (250 mg/Kg)-treated rats and 920 for AAP (500 mg/kg)-treated rats. Data represent mean ± SEM of the percentage of TUNEL positive cells in 12 image fields from 2 different animals for each condition. ***p<0.001 as compared to vehicle treated animals.