Figure 5. Effect of SaDRD1 knockdown on Na⁺/K⁺-ATPase (NKA activity) in cultured S. argus primary kidney cells (40 hours post-transfection).

(A) SaDRD1 mRNA was dramatically reduced by si-SaDRD1 as determined by RT-qPCR, resulting in the upregulation of NKA activity in cultured primary kidney cells. (B) Expression of SaDRD1 protein in renal primary cells was significantly inhibited by si-SaDRD1 (a-c) compared to the negative control (si-N.C., d-f). Conversely, treatment of renal primary cells with si-SaDRD1 increased expression of NKA α1 (g-i) relative to control cells (si-N.C., j-l). Positive control without any siRNA treatment was set for locating NKA α1 (m-o). Scale bar = 10 μm.