Immunolocalization of aquaporin chip in the guinea pig inner
ear.
Stankovic, Konstantina M., Joe C. Adams, Dennis Brown.
Harvard-Massachusetts Institute of Technology Division of Health
Sciences and Technology, and Eaton-Peabody Laboratory, Massachusetts
Eye and Ear Infirmary, Boston, Massachusetts 02114, Department of
Otology and Laryngology, Harvard Medical School and Massachusetts Eye
and Ear Infirmary, Boston, Massachusetts 02114 , The Renal Unit,
Massachusetts General Hospital, and Department of Pathology, Harvard
Medical School, Boston, Massachusetts 02114
APStracts 2:0221C, 1995.
Aquaporin CHIP (AQP-CHIP) is a water channel protein previously
identified in red blood cells and water transporting epithelia. The
inner ear is an organ of hearing and balance whose normal function
depends critically on maintenance of fluid homeostasis. In this
study, AQP-CHIP, or a close homologue was found in specific cells of
the inner ear, as assessed by immunocytochemistry using affinity
purified polyclonal antibodies against AQP-CHIP. AQP-CHIP was
predominantly found in fibrocytes in close association with bone,
including most of the cells lining the bony labyrinth and in
fibrocytes lining the endolymphatic duct and sac. AQP-CHIP-positive
cells not directly apposing bone include cells under the basilar
membrane, some type III fibrocytes of the spiral ligament, fibrocytes
of the spiral limbus, and the trabecular perilymphatic tissue
extending from the membranous to the bony labyrinth. AQP-CHIP was
also found in the periosteum of the middle ear and cranial bones, as
well as in chondrocytes of the oval window and stapes. The
distribution of AQP-CHIP in the inner ear suggests that AQP-CHIP may
have special significance for maintenance of bone and the basilar
membrane, and for function of the spiral ligament.
Received 20 September 1994; accepted in final form 26 May 1995.
APS Manuscript Number C564-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 June 1995.