Somatostatin (somatostatinlike) immunoreactive cells in the human inner ear

Certain epithelia of the human inner ear and human endolymphatic sac display somatostatin and/or somatostatin-like immunoreactivity. Histologic sections from 13 human temporal bones and from 15 endolymphatic sacs were studied using the unlabeled antibody peroxidase-antiperoxidase technique. The somatostatin and/or somatostatin-like immunoreactive cells were located exclusively in the covering epithelium of the spiral prominence and in the epithelium of the intermediate and rugosal part of the endolymphatic sac. In the epithelium of the spiral prominence and endolymphatic sac, secretory granules of the same size and appearance as those of intestinal or pancreatic somatostatin-producing cells were demonstrated ultrastructurally. The findings are consistent with a local exocrine, paracrine, and/or endocrine system of the inner ear.