Vagotomy upregulates expression of the N-methyl-D-aspartate receptor NR2D subunit in the stomach.
BACKGROUND
N-methyl-D-aspartate (NMDA) receptor is the major excitatory neurotransmitter receptor in the central nervous system. Recent evidence has pointed to expression of NMDA receptor in peripheral non-neuronal tissues and organs; however, little is known about the expression of the receptor in the stomach. The present study identified what types of NMDA receptor subunits are expressed in the rat stomach and examined whether vagotomy affects their expression.


METHODS
To see the expression and distribution of the mRNAs and proteins for the NMDA receptor subunits, real-time reverse transcription-polymerase chain reaction, Western blotting, in situ hybridization, and immunohistochemistry were carried out on rat stomach with and without vagotomy.


RESULTS
Of the NMDA receptor subunits, NR1, NR2 (2A, 2B, 2C, 2D), and NR3 (3A, 3B), all NR subunit mRNAs except for the NR2B subunit mRNA were expressed in the intact rat stomach, with huge expression of NR2D mRNA. Expression of NR2D subunit mRNA and protein significantly increased after vagotomy. Increased expression was found in mucosal cells, the myenteric plexus, and the outer membrane of the stomach with vagotomy.


CONCLUSIONS
Vagotomy upregulates expression of the NR2D subunit in the stomach and therefore, the NR2D subunit may be implicated in gastric motility.
Watanabe
Kanako
K
Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan.
Kanno
Takeshi
T
Oshima
Tadayuki
T
Miwa
Hiroto
H
Tashiro
Chikara
C
Nishizaki
Tomoyuki
T
D000818:Animals; D015153:Blotting, Western; D005746:Gastric Emptying / Q000502:physiology*; D005753:Gastric Mucosa / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D009130:Muscle, Smooth / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000294:innervation*; D015854:Up-Regulation; D014628:Vagotomy / Q000379:methods*
C464436:NR2D NMDA receptor; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate