Intracisternal TRH analog induces Fos expression in gastric myenteric neurons and glia in conscious rats.
Activation of gastric myenteric cells by intracisternal injection of the stable thyrotropin-releasing hormone (TRH) analog RX-77368, at a dose inducing near maximal vagal cholinergic stimulation of gastric functions, was investigated in conscious rats. Fos immunoreactivity was assessed in gastric longitudinal muscle-myenteric plexus whole mount preparations 90 min after intracisternal injection. Fos-immunoreactive cells were rare in controls (~1 cell/ganglion), whereas intracisternal RX-77368 (50 ng) increased the number to 24.8 +/- 1.8 and 26.8 +/- 2.2 cells/ganglion in the corpus and antrum, respectively. Hexamethonium (20 mg/kg sc) prevented Fos expression by 90%, whereas atropine (2 mg/kg sc) had no effect. The neuronal marker protein gene product 9.5 and the glial markers S-100 and glial fibrillary acidic proteins showed that RX-77368 induced Fos in both myenteric neurons and glia. Vesicular ACh transporter and calretinin were detected around the activated myenteric neurons. These results indicated that central vagal efferent stimulation by intracisternal RX-77368 activates gastric myenteric neurons as well as glial cells mainly through nicotinic ACh receptors in conscious rats.
Miampamba
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M
CURE: Digestive Diseases Research Center, Veterans Affairs Greater Los Angeles Healthcare System, 11301 Wilshire Blvd., Bldg 115, Rm. 203, Los Angeles, CA 90073, USA. mmiampamba@ucla.edu
Yang
H
H
Sharkey
K A
KA
Taché
Y
Y
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000032:analysis; D002946:Cisterna Magna; D004525:Efferent Pathways / Q000502:physiology; D016762:Genes, fos / Q000187:drug effects*; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D018738:Hexamethonium / Q000494:pharmacology; D008297:Male; D026901:Membrane Transport Proteins; D008845:Microinjections; D009197:Myenteric Plexus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000502:physiology; D011978:Receptors, Nicotinic / Q000502:physiology; D009418:S100 Proteins / Q000032:analysis; D013270:Stomach / Q000294:innervation*; D013869:Thiolester Hydrolases / Q000032:analysis; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D043222:Ubiquitin Thiolesterase; D014630:Vagus Nerve / Q000502:physiology; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
D015415:Biomarkers; D002352:Carrier Proteins; D005904:Glial Fibrillary Acidic Protein; D026901:Membrane Transport Proteins; D016760:Proto-Oncogene Proteins c-fos; D011976:Receptors, Muscarinic; D011978:Receptors, Nicotinic; D009418:S100 Proteins; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D018738:Hexamethonium; D013973:Thyrotropin-Releasing Hormone; C027979:L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; D001285:Atropine; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase; D011761:Pyrrolidonecarboxylic Acid