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.

Alkaline phosphatase activity in the inner ear of fetuses, newborn and adult guinea pigs

The distribution pattern of alkaline phosphatase in the inner ear of fetuses, newborn and adult guinea pigs is described. In the inner ear of fetuses, remarkable alkaline phosphatase was noted throughout the entire tissue of spiral ligament, statoacoustic nerve fibers and the wall of small blood vessels. In newborns, however, less enzyme activity was seen in the spiral ligament and statoacoustic nerve. In adult guinea pigs, no enzyme activity was detectable in the spiral ligament and statoacoustic nerve fibers except for the wall of small blood vessels and efferent nerve fibers. It is evident that the distribution pattern of alkaline phosphatase is altered during the development of the inner ear of the guinea pig.