Glutamate and NO mediation of the pressor response to 5-HT3 receptor stimulation in the nucleus tractus solitarii.
The possible participation of glutamate and NO/cGMP in the pressor response to 5-HT3 receptor activation in the nucleus tractus solitarii (NTS) was investigated using selective antagonists in urethane-anaesthetized rats. Intra-NTS administration of NMDA and non-NMDA receptor antagonists, but not metabotropic glutamate receptor antagonists, markedly reduced (70%) the increase in blood pressure caused by local application of the potent 5-HT3 receptor agonist, 1-(m-chlorophenyl)-biguanide. The 5-HT3 receptor-mediated pressor response was also significantly attenuated by the local blockade of nitric oxide synthase and soluble guanylyl cyclase. These data suggest that ionotropic glutamate receptors and the associated NO/cGMP transduction mechanism contribute downstream to the pressor effect elicited by 5-HT3 receptor stimulation in the NTS.
Sévoz-Couche
Caroline
C
INSERM U.288, CHU Pitié-Salpêtrière, 91 blvd de l'Hôpital, 75634 Paris Cedex 13, France.
Maisonneuve
Boris
B
Hamon
Michel
M
Laguzzi
Raul
R
D000818:Animals; D001645:Biguanides / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010069:Oxadiazoles / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000378:metabolism; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D044406:Receptors, Serotonin, 5-HT3; D012018:Reflex / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000378:metabolism; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D017552:Solitary Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
C116907:1H-(1,2,4)oxadiazolo(4,3-a)-quiloxalin-1-one; D001645:Biguanides; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D007191:Indazoles; D010069:Oxadiazoles; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D011985:Receptors, Serotonin; D044406:Receptors, Serotonin, 5-HT3; D017366:Serotonin Receptor Agonists; D009569:Nitric Oxide; D012701:Serotonin; D018698:Glutamic Acid; C065734:1-(3-chlorophenyl)biguanide; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; C080122:7-nitroindazole