The inner ear produces a natriuretic hormone.
Qvortrup, Klaus, Jr.gen Rostgaard Niels-Henrik Holstein-Rathlou.
Department of Medical Anatomy, University of Copenhagen, The Panum
Institute, Blegdamsvej, DK- 2200 Copenhagen N, Denmark, Department of
Medical Physiology, University of Copenhagen, The Panum Institute, 3
Blegdamsvej, DK-2200 Copenhagen N, Denmark, Department of Oto-rhino
-laryngology, Head & Neck Surgery, Rigshospitalet, 9 Blegdamsvej,
DK-2100, Denmark
APStracts 3:0055F, 1996.
Cytoplasmic granules have been demonstrated in epithelial cells from
the endolymphatic sac, an extraosseus part of the inner ear located
in the posterior cranial fossa. Intravenously infused extracts from
endolymphatic sacs in anesthetized rats elicited a potent natriuresis
and diuresis without effects on blood pressure, glomerular filtration
rate or lithium clearance. Only a minor kaliuresis was observed.
Extracts of dural tissue adjacent to the endolymphatic sacs had no
effect. It is concluded that the endolymphatic sac contains an
endogenous inhibitor of sodium reabsorption and could be the sensory
organ/mediator of "cerebral" natriuresis. Furthermore, this
substance, tentatively named saccin, may influence the homeostasis of
the inner ear fluids and accordingly play a significant role in the
pathogenesis of M[acute]eni[grave]ere's disease.
Received 16 November 1995; accepted in final form 11 March 1996.
APS Manuscript Number F6-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 27 March 96