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Immunohistochemical localization of voltage‐activated calcium channels in the rat oesophagus
Author(s) -
DE LAET A.,
ADRIAENSEN D.,
VAN BOGAERT PP.,
SCHEUERMANN D. W.,
TIMMERMANS JP.
Publication year - 2002
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1046/j.1365-2982.2002.00320.x
Subject(s) - myenteric plexus , enteric nervous system , immunohistochemistry , calcium , voltage dependent calcium channel , calcium channel , depolarization , l type calcium channel , chemistry , biology , medicine , endocrinology , anatomy
Voltage‐activated calcium channels play an important role in the physiology of the enteric nervous system. To determine which types of voltage‐activated calcium channels are present in the rat oesophagus, an immunohistochemical study was performed using specific antibodies for the alpha 1 subunits of Ca v 2.1 (P/Q‐type), Ca v 2.2 (N‐type), Ca v 1.2 and Ca v 1.3 (L‐type) calcium channels. All myenteric cell bodies showed Ca v 2.2 immunoreactivity, whereas labelling for this N‐type channel was absent in nerve fibres. Ca v 1.2 immunoreactivity was found on nerve fibres in the myenteric plexus and on fibres innervating the striated muscle of the rat oesophagus, whereas no labelling was detected on neuronal somata. Immunoreactivity against Ca v 1.3 was not detected in the myenteric plexus or at the level of the striated muscle. Labelling for Ca v 2.1 was absent at the level of the myenteric plexus, but present in the striated muscle layer at the level of the motor endplates. Comparison with recent literature data from rat small intestine reveals region‐specific distribution patterns of the various subtypes of voltage‐activated calcium channels within the enteric nervous system. In addition, the present immunohistochemical data corroborate our physiological data (see accompanying paper), which indicate that the Ca v 2.2 (N‐type) channel is the predominant channel involved in the generation of the calcium‐dependent action potential evoked by intrasomatic depolarizing current pulses in all rat oesophageal myenteric neurones.