Objectives/hypothesis: The function of the human endolymphatic sac (ES) has been enigmatic for decades. Hypotheses include controlling endolymphatic fluid homeostasis and inner ear immunological defense. Additionally, several studies indicate a possible endocrine capacity and a yet undefined role in intracranial pressure homeostasis. However, no direct evidence of such capacity exists. This study aims to explore and identify the hypothesized endocrine capacity of the human ES.
Study Design: DNA microarrays and immunohistochemistry were used for analyses of fresh human ES tissue samples.
Methods: Twelve tissue samples from the human ES were obtained during translabyrinthine surgery for vestibular schwannoma. Microarray technology was used to investigate tissue sample gene expression. Genes specific for an endocrine function were determined, and results were verified by immunohistochemistry.
Results: Several natriuretic peptides were found expressed significantly in the ES, including uroguanylin and brain natriuretic peptide, but also peptides regulating vascular tone, including adrenomedullin 2. In addition, both neurophysin and oxytocin (OXT) were found significantly expressed. All peptides were verified by immunohistochemistry.
Conclusion: The present data support the hypothesis that the human ES may have an endocrine/paracrine capacity through expression of several peptides with potent natriuretic activity. Furthermore, the ES may influence the hypothalamo-pituitary-adrenal axis and may regulate vasopressin receptors and aquaporin-2 channels in the inner ear via OXT expression. We hypothesize that the ES is likely to regulate inner ear endolymphatic homeostasis, possibly through secretion of several peptides, but it may also influence systemic and/or intracranial blood pressure through direct and indirect action on the vascular system and the kidney.
Level Of Evidence: NA. Laryngoscope, 127:E201-E208, 2017.
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http://dx.doi.org/10.1002/lary.26074 | DOI Listing |
Otol Neurotol
January 2025
Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland.
Objective: We aimed to investigate the effect of adding "rapid decelerations" and "vibrations" during a SemontPLUS maneuver on the dynamics of the inner ear and the success rate of canalolithiasis repositioning.
Methods: We used a previously described upscaled (5×) in vitro model of the posterior semicircular canal of the inner ear to analyze the trajectory of a single and clumped surrogate otolith particle (metallic sphere) during a SemontPLUS maneuver (-60 degrees below earth horizontal) on a repositioning chair (TRV). We compared the angular displacement of these particles with and without the application of "vibrations" or "rapid decelerations" using TRV.
Environ Sci Technol
January 2025
State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
The effects of particulate matter (PMs) from different cities on the nervous system remain unclear. In this study, aqueous solutions of 0.45 μm membrane-filtered PM from 31 major Chinese cities were intravenously administered to rats.
View Article and Find Full Text PDFJ Comput Assist Tomogr
January 2025
Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL.
Treacher Collins syndrome (TCS) is an uncommon congenital disorder predominantly involving craniofacial, orbital, and otological structures. The various ear malformations seen in 9 patients with TCS are described. TCS predominantly affects the external and middle ear structures, with inner ear structures being relatively spared, not unexpected given the dual embryological origin of the human ear.
View Article and Find Full Text PDFHear Res
January 2025
CHU Lille, Department of Otology and Neurotology, F-59000 Lille, France; Univ. Lille, France; Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France.
Objective: The aim of this study is to detail and evaluate the surgical procedure for perilymph sampling from the cochlear apex in the Mongolian gerbil.
Design: Perilymph sampling from the cochlear apex was performed one to three time in 12 male gerbils aged 8 to 12 months via the submandibular route. 11 of them were previously implanted with intracochlear implants loaded with dexamethasone and placed in the scala tympani, the 12th was used to collect control samples.
J Acoust Soc Am
January 2025
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
The otic capsule and surrounding temporal bone exhibit complex 3D motion influenced by frequency and location of the bone conduction stimulus. The resultant correlation with the intracochlear pressure is not sufficiently understood, thus is the focus of this study, both experimentally and numerically. Experiments were conducted on six temporal bones from three cadaver heads, with BC hearing aid stimulation applied at the mastoid and classical BAHA locations across 0.
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