Immunohistochemical study of peripolar cells of the sheep.

The proposal that the cytoplasmic granules of glomerular peripolar cells (PPCs) of the adult sheep and lamb contain a kallikrein-like substance has been re-examined. After extensive characterisation and purification of anti-kallikrein antibodies, it was concluded that PPCs do not contain immunohistochemically detectable amounts of urinary kallikrein; nor do such cells appear to synthesise kallikrein as shown by hybridisation histochemistry studies. They are also not renin-immunopositive. On the other hand, a proportion of them exhibit neuron-specific enolase (NSE) immunoreactivity, unlike the apparently closely related visceral and parietal epithelial cells.