Role of nerve growth factor in modulation of gastric afferent neurons in the rat.
Recent studies demonstrated that experimental ulcers are associated with changes in the properties of voltage-sensitive sodium currents in sensory neurons. We hypothesized that nerve growth factor (NGF) contributes to these changes. Gastric ulcers were induced by acetic acid injection into the wall of the rat stomach. NGF expression was determined by ELISA and immunohistochemically. Sensory neurons were labeled by injection of a retrograde tracer into the gastric wall. Sodium currents were recorded in gastric sensory neurons from nodose and dorsal root ganglia cultured for 24 h in the presence of NGF or a neutralizing NGF antibody, respectively. Gastric ulcer formation caused a rise in NGF concentration within the gastric wall and an increase in NGF immunoreactivity. Exposure to NGF caused a significant increase in the TTX-resistant sodium current, whereas the TTX-sensitive sodium current remained unchanged. This was associated with an acceleration of the recovery from inactivation in spinal sensory neurons. Production and release of NGF in the gastric wall may contribute to sensitization of primary afferent neurons during gastric inflammation.
Bielefeldt
K
K
Department of Internal Medicine, 4614 JCP, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242, USA. klaus-bielefeldt@uiowa.edu
Ozaki
N
N
Gebhart
G F
GF
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005753:Gastric Mucosa / Q000473:pathology; D006930:Hyperalgesia / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D020932:Nerve Growth Factor / Q000494:pharmacology*; D009475:Neurons, Afferent / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000187:drug effects; D013270:Stomach / Q000187:drug effects / Q000294:innervation* / Q000473:pathology; D013276:Stomach Ulcer / Q000139:chemically induced / Q000503:physiopathology; D013779:Tetrodotoxin / Q000494:pharmacology
D000779:Anesthetics, Local; D015222:Sodium Channels; D013779:Tetrodotoxin; D020932:Nerve Growth Factor