Fig. 2.
Inner medullary collecting duct (IMCD) principal cells label positively for proliferating cell nuclear antigen (PCNA) during early lithium treatment. Shown are representative images from kidney inner medullary tissue (IM-3) stained for the proliferation marker PCNA (green) and the renal principal cell marker, aquaporin-4 (AQP4) (red) in untreated rats (A), 1-wk lithium-treated rats (B), 2-wk lithium-treated rats (C), and 12-wk lithium-treated rats (D). Nuclei are stained blue with DAPI; n = 3.