Microinjection of l-glutamate into the nucleus ambiguus partially inhibits gastric motility through the NMDA receptor - nitric oxide pathway.
We have previously reported that both l-glutamate (l-Glu) and nitric oxide (NO) modulate gastric motility in the nucleus ambiguus (NA). The aim of this study is to explore the potential correlation between the l-Glu and NO. A latex balloon connected to a pressure transducer was inserted into the pylorus through the fundus of anesthetized male Wistar rats to continuously record changes in gastric smooth muscle contractile curves. Pretreatment with the NO-synthase inhibitor N-nitro-l-arginine methylester (l-NAME) did not completely abolish the inhibitory effect of l-Glu on gastric motility, but intravenous injection of the ganglionic blocker hexamethonium bromide (Hb) did. By using a specific N-methyl-d-aspartic acid (NMDA) receptor antagonist, we blocked the inhibitory effect of the NO-donor sodium nitroprusside (SNP) on gastric motility. These results suggest that microinjections of l-Glu into the NA inhibits gastric motility by activating the cholinergic preganglionic neurons, partially through the NMDA receptor - NO pathway.
a College of Life Science, Qi Lu Normal University, No. 36, Lishan Road, Jinan, Shandong 250013, P.R. China.
Hong-Zhao
HZ
Sun
Shu-Zhen
SZ
Zhao
Hong-Bin
HB
Ai
D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005730:Ganglionic Blockers / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects* / Q000502:physiology; D018698:Glutamic Acid / Q000008:administration & dosage* / Q000494:pharmacology*; D018738:Hexamethonium / Q000494:pharmacology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects* / Q000502:physiology*; D008845:Microinjections; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000008:administration & dosage / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013270:Stomach / Q000187:drug effects / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D005730:Ganglionic Blockers; D018377:Neurotransmitter Agents; D020030:Nitric Oxide Donors; D016194:Receptors, N-Methyl-D-Aspartate; D009599:Nitroprusside; D009569:Nitric Oxide; D018738:Hexamethonium; D018698:Glutamic Acid; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester
L-glutamate; NMDA receptor; gastric motility; l-glutamate; motilité gastrique; nitric oxide; noyau ambigu; nucleus ambiguus; oxyde nitrique; récepteur NMDA