Expression of histamine receptors and effect of histamine in the rat carotid body chemoafferent pathway

Eur J Neurosci. 2006 Dec;24(12):3431-44. doi: 10.1111/j.1460-9568.2006.05241.x.

Abstract

Chemosensory information from peripheral arterial oxygen sensors in the carotid body is relayed by petrosal ganglion neurons to the respiratory networks in the medulla oblongata. Biogenic amines, including histamine, released from glomus (type I) cells of the carotid body are considered to be primary transmitters in hypoxic chemosensitivity. Immunocytochemistry at light-and electron-microscopical levels, and RT-PCR, revealed the expression of histamine receptors 1 and 3 as well as histidine decarboxylase in the rat carotid body glomus cells and petrosal ganglion neurons. Histamine receptors 1 and 3, but not histidine decarboxylase, were also observed in the ventrolateral, intermediate and commissural subnuclei of the nucleus tractus solitarii in the medulla oblongata. In order to examine the possible role of histamine in the afferent branch of the respiratory system, we applied histamine receptor 1 and 3 agonists to the carotid body, which caused a mildly increased phrenic nerve activity in a working heart-brainstem preparation. Moreover, microinjection of antagonists of histamine receptors 1 and 3 into the nucleus tractus solitarii caused significant changes in the inspiratory timing and the chemoreceptor response. Our data show that histamine acting via histamine receptors 1 and 3 plays an important neuromodulatory role in the afferent control of chemosensitivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Afferent Pathways* / drug effects
  • Afferent Pathways* / metabolism
  • Amidines / metabolism
  • Animals
  • Blotting, Northern / methods
  • Carotid Body / drug effects*
  • Carotid Body / metabolism
  • Carotid Body / ultrastructure
  • Chemoreceptor Cells / drug effects
  • Female
  • Gene Expression / drug effects*
  • Gene Expression / physiology
  • Histamine / pharmacology*
  • Histamine Antagonists / pharmacology
  • Histidine Decarboxylase / metabolism
  • Immunohistochemistry / methods
  • Male
  • Medulla Oblongata / drug effects
  • Microscopy, Immunoelectron / methods
  • Phrenic Nerve / drug effects
  • Phrenic Nerve / physiology
  • Piperidines / pharmacology
  • Pyrilamine / pharmacology
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Histamine / genetics
  • Receptors, Histamine / metabolism*
  • Respiration / drug effects
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Sodium Cyanide / pharmacology

Substances

  • Amidines
  • Histamine Antagonists
  • Piperidines
  • RNA, Messenger
  • Receptors, Histamine
  • diamidino compound 253-50
  • Histamine
  • Histidine Decarboxylase
  • Pyrilamine
  • thioperamide
  • Sodium Cyanide