Metallothionein reduced histopathological manifestations of CIA. On day 34 postimmunization, mice (n = 15 per group) were sacrificed and right hindpaws were removed. The specimens were fixed, decalcified, embedded in paraffin, sectioned, and stained with haematoxylin and eosin. (a) Joints of normal mice; (b) mainly normal joints from metallothionein-treated mice; (c) moderately arthritic joints from metallothionein-treated mice; (d) severely arthritic joints from vehicle-treated mice. Original magnification: ×40. Percentage of histological score per group is shown in (e). □ Normal; moderate; ▪ severe.