Temporal kinetics of organ damage in copper toxicity: A histopathological correlation in rat model

Excess of copper is toxic to different organs. We aim to study the histopathological changes of liver, kidney, and brain following oral CuSO4 exposure for different duration and doses in rat model. Fifty-four males Wistar rats (205 ± 10 g) were included and divided into control (group-I) and experimental (group-II and III) arms. An oral dose of 100 and 200 mg/kgBWt/Day CuSO4 was given to group-II and III respectively and group-I received normal saline by gavage. Six rats from each group were sacrificed on days 30, 60 and 90 for biochemical and histopathological examinations. The histopathological changes were graded on 1-5 scores and correlated with respective laboratory parameters. The organ functions were worsened in experimental group with increasing dose and time. Histopathological study revealed edema, hemorrhage, necrosis and fibrosis/gliosis in experimental group. The worst histopathological severity score ranged from 4 to 5(median 5) in liver, 3-5(median 4) in kidney and 4-5(median 5) in brain. The edema and hemorrhage were more marked at 30 days and fibrosis/gliosis at 90 days. In conclusion, high-dose Cu toxicity results in structural damage to liver, kidney, and brain that correlates with organ dysfunction, Cu, GSH, TAC, and MDA concentrations. Liver damage is more severe and occurs earlier than other organs.