Alkaline phosphatase activity in the inner ear blood vessels of some mammals

The distribuation pattern of alkaline phosphatase in small blood vessels was studied histochemically in the stria vascularis and spiral ligament of various mammals. No or extremely weak activity of the enzyme was demonstrated in the walls of the blood vessels in bat and rabbit, while moderate to intense activity was found in guinea pig, cat, squirrel monkey and man. There was a species difference in the phosphate metabolism in the walls of the inner ear blood vessels.