Figure 7 A photomicrograph of renal tissue sections stained immunohistochemically with caspase-3 antibody. (a) Normal Caspase-3 activity. (b) Rats treated with toluene show marked increase of caspase-3 activity, especially in tubular epithelium. (c) Rats treated with toluene and 150 mg citicoline shows positive caspase-3 activity is still noticed. (d) Rats treated with toluene and 300 mg citicoline show marked decrease in caspase-3 activity in tissue when compared with the group treated with toluene only (caspase-3 antibody, ×400).