Presence of alkaline phosphatase and gamma-glutamyl transpeptidase on the parietal layer of Bowman's capsule.

Generally, the parietal layer of Bowman's capsule in the mammal kidney consists of a squamous epithelium resting upon a basement lamina. However, tall cylindrical cells resembling those of the proximal tubules were observed on the outer wall of Bowman's capsule in the mouse and rat kidneys. These cells were provided with an apical brush border and were positive for alkaline phosphatase and gamma-glutamyl transpeptidase suggesting phosphate and amino acid transport at the capsular level.