Expression of carbonic anhydrase isoenzyme-like immunoreactivity in the limbus spiralis of the human fetal cochlea.

The distribution of carbonic anhydrase isoenzymes (CA I, II, III, V) was analyzed the 14-, 15- and 16-week-old human fetal cochleae using immunohistochemical methods. The interdental cells in the limbus spiralis were strongly labelled with antibodies against CA I and III and the spiral ligament was also positive for CA I and III. The stria vascularis and organ of Corti were however negative for CA I, II, III and V. These results suggest that the interdental cells in the human fetus may be related to fluid and ion transport of endolymph especially in the early stages of development.