Histochemistry of the juxtaglomerular apparatus in the toad Bufo bufo. Acid phosphatase activity of the epitheloid cells in the glomerular afferent arterioles.

Histochemical techniques for acid phosphatase activity applied to kidney tissue of the toad Bufo bufo demonstrate that a high enzyme activity is present in the dense granules of the proximal tubule cells, but also in the media cells in the wall of the glomerular afferent arterioles. The acid phosphatase activity is confined to the characteristic granules in these juxtaglomerular cells, which therefore are lysosomal in nature.