Figure 2.

Low-power micrograph of RhCG expression in the human kidney. (A) Low-power magnification of RhCG immunoreactivity in human kidney cortex. Immunoreactivity is present in a subset of convoluted tubule segment and in collecting duct epithelia. No expression is observed in proximal tubule epithelia (PT) or glomeruli (G). (B) Preincubation of the antibody with the immunizing peptide blocked immunoreactivity. (C) Rhcg expression in convoluted tubule segments in the human cortex. Both apical and basolateral Rhcg immunoreactivity is clearly present. Essentially all cells express Rhcg, and a subset of cells demonstrates increased immunoreactivity. (D) Expression in the cortical collecting duct (CCD). In contrast to convoluted tubule and initial collecting duct segments, only a subset of CCD cells expresses detectable RhCG immunoreactivity. These cells tend to be larger, protrude into the tubule lumen, and have morphologic characteristics suggestive of intercalated cells. (E) Expression in the outer medullary collecting duct in the inner stripe. Both apical and basolateral immunoreactivity is present in only a subset of cells (arrows). Basolateral immunoreactivity in these cells appears to be more intense than the apical immunoreactivity. (F) Expression in the inner medullary collecting duct. Only a minority of cells expresses Rhcg immunoreactivity (arrows); both apical and basolateral Rhcg immunoreactivity is present in these cells.