The Effect of Copper Sulfate on Aquaporins in Kidney Tissue

Copper (Cu) is a cofactor for most enzymes and an essential trace element. However, elevated levels of Cu exposure cause toxic effects in various tissues. Aquaporins (AQP) are integral membrane proteins that play a key role in fluid transport, particularly in kidney tissues. In our study, we aimed to evaluate the expression of AQP-1, -2, and -3 in the kidneys of female and male rats following the administration of high-dose copper sulfate (CuSO4). First, the control group (n=10) received saline via oral gavage, while the experimental group (CuSO4) (n=10) received 100 mg/kg/day via oral gavage for 14 days. Histopathological, PAS staining, and immunohistochemical evaluation of AQP-1, -2, and -3 were then performed on kidney tissues from the control and experimental groups. CuSO4 caused tubular vacuolization in the kidneys. CuSO4 administration decreased AQP-2 levels while increasing AQP-1 and AQP-3 levels. These findings suggest that CuSO4 may have re-modulated AQP-1 and AQP-3 levels due to the tubular vacuolization and degeneration it caused; however, the effect of CuSO4 on estrogen levels in females and the vasopressin effect via AQP-2 need to be investigated in detail.