Immunohistochemical localization of histamine receptors in rat cochlea.

Abstract

OBJECTIVE:

Histamine may have physiologic functions in the inner ear. The locations of histamine receptors, however, have not yet been identified in the mammalian cochlea. The aim of this study was to investigate the localization of histamine receptor subtypes (H1, H2, and H3 receptors) in rat cochlea.

METHODS:

Immunohistochemistry was performed with antibodies specific for each of the histamine receptors (H1, H2, and H3). To identify the type I and II spiral ganglion cells in the cochlea, some cryostat sections were double stained with antibodies to both a histamine receptor and neurofilament 200 kD, which predominantly stains type II spiral ganglion cells in the cochlea.

RESULTS:

All H1, H2, and H3 receptor immunoreactive staining was limited to the spiral ganglion cells of the cochlea. Spiral ganglion cells with positive immunoreactivity to the neurofilament 200 kD antibody were stained only slightly by histamine H1, H2, and H3 receptor antibodies, indicating that histamine receptor immunoreactivity is specific to type I ganglion cells.

CONCLUSIONS:

These findings indicate that histamine receptors are present in the cochlea and support the hypothesis that histamine plays a physiologic role in the cochlea.

• Authors: Hiroshi Azuma, Shoichi Sawada, Shunji Takeuchi, Kasumi Higashiyama, Akinobu Kakigi, Taizo Takeda
• Journal: The Laryngoscope (Laryngoscope) Vol. 114 Issue 12 Pg. 2249-51 (Dec 2004) ISSN: 0023-852X [Print] United States
• PMID: 15564855 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Histamine
• Receptors, Histamine H1
• Receptors, Histamine H2
• Receptors, Histamine H3

Topics

• Animals
• Cochlea (anatomy & histology, ultrastructure)
• Female
• Immunohistochemistry
• Microscopy, Confocal
• Models, Animal
• Rats
• Rats, Wistar
• Receptors, Histamine (analysis)
• Receptors, Histamine H1 (analysis)
• Receptors, Histamine H2 (analysis)
• Receptors, Histamine H3 (analysis)
• Sensitivity and Specificity