Panel A: Absence of Na, K-ATPase α2, α3 and γ isoform expression and comparison with α1 expression in canine prostate. Original magnifications: × 800. Panel B: Evidence to confirm that the γ C33 polyclonal raised against the rodent γ isoform recognizes the canine γ isoform protein in the canine kidney. The expression of the γ isoform is not detected in all nephron segments (i.e. medullary and papillary collecting ducts) but it is present in low levels in proximal convoluted tubules and in high levels in the medullary thick ascending limbs, and the distal nephron.