PMID- 7965835
OWN - NLM
STAT- MEDLINE
DCOM- 19941208
LR  - 20190512
IS  - 0022-3751 (Print)
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 478 ( Pt 1)
IP  - Pt 1
DP  - 1994 Jul 1
TI  - In vivo release of glutamate in nucleus tractus solitarii of the rat during 
      hypoxia.
PG  - 55-66
AB  - 1. An attempt has been made to test the hypothesis that, in the caudal part of 
      nucleus tractus solitarii (NTS) where carotid sinus nerve (CSN) afferents 
      project, L-glutamate (Glut) modulates the hypoxic ventilatory response. 2. 
      Unanaesthetized, peripherally chemodenervated (carotid body denervated; CBD) and 
      sham-operated, freely moving rats were used. During peripheral chemoreceptor 
      stimulation by hypoxia (10% O2 for 30 min) or doxapram (Dox) infusion (2 mg kg-1 
      (30 min)-1), ventilation was recorded and successively, under the same 
      conditions, the extracellular Glut concentration ([Glut]o) in the caudal NTS was 
      measured by in vivo microdialysis. [Glut]o was also measured during hyperoxic 
      hypercapnia (10% CO2-30% O2 for 30 min). 3. Furthermore, the effects on 
      ventilation of exogenous Glut, the NMDA (N-methyl-D-aspartate) receptor 
      antagonist MK-801 or the ionotropic receptor antagonist kynurenate microinjected 
      into the caudal NTS were investigated in sham-operated rats. 4. In sham-operated 
      rats, both ventilation and [Glut]o in NTS were increased during peripheral 
      chemoreceptor stimulation. On the other hand, no increases in either ventilation 
      or Glut release were observed in CBD rats. In spite of ventilatory augmentation 
      during hypercapnia, no response of [Glut]o to hypercapnia was observed in either 
      group. 5. Local Glut application into NTS increased ventilation. Pretreatment 
      with MK-801 or kynurenate reduced the hypoxic ventilatory response. This 
      reduction in ventilation was mainly due to the decrease in tidal volume. 6. These 
      results suggest that hypoxia induced the release of Glut in NTS and that this 
      effect was mediated by arterial chemosensory input.
FAU - Mizusawa, A
AU  - Mizusawa A
AD  - First Department of Internal Medicine, Tohoku University School of Medicine, 
      Sendai, Japan.
FAU - Ogawa, H
AU  - Ogawa H
FAU - Kikuchi, Y
AU  - Kikuchi Y
FAU - Hida, W
AU  - Hida W
FAU - Kurosawa, H
AU  - Kurosawa H
FAU - Okabe, S
AU  - Okabe S
FAU - Takishima, T
AU  - Takishima T
FAU - Shirato, K
AU  - Shirato K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
RN  - 3KX376GY7L (Glutamic Acid)
RN  - 6LR8C1B66Q (Dizocilpine Maleate)
RN  - 94F3830Q73 (Doxapram)
RN  - H030S2S85J (Kynurenic Acid)
SB  - IM
MH  - Animals
MH  - Blood Pressure/drug effects
MH  - Carotid Body/physiology
MH  - Chemoreceptor Cells/physiology
MH  - Denervation
MH  - Dizocilpine Maleate/administration & dosage/pharmacology
MH  - Doxapram/administration & dosage/pharmacology
MH  - Glutamic Acid/administration & dosage/*metabolism/pharmacology
MH  - Heart Rate/drug effects
MH  - Hypoxia/*physiopathology
MH  - Infusions, Intravenous
MH  - Kynurenic Acid/administration & dosage/pharmacology
MH  - Male
MH  - Microinjections
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Respiration
MH  - Solitary Nucleus/drug effects/*physiology/physiopathology
PMC - PMC1155644
EDAT- 1994/07/01 00:00
MHDA- 1994/07/01 00:01
PMCR- 1994/07/01
CRDT- 1994/07/01 00:00
PHST- 1994/07/01 00:00 [pubmed]
PHST- 1994/07/01 00:01 [medline]
PHST- 1994/07/01 00:00 [entrez]
PHST- 1994/07/01 00:00 [pmc-release]
AID - 10.1113/jphysiol.1994.sp020229 [doi]
PST - ppublish
SO  - J Physiol. 1994 Jul 1;478 ( Pt 1)(Pt 1):55-66. doi: 
      10.1113/jphysiol.1994.sp020229.