Epithelium-dependent effect of L-glutamate on airways: involvement of prostaglandins.
We investigated the effect of the excitatory amino acid (EAA) receptor agonists L-glutamate, N-methyl-D-aspartate (NMDA), (RS)-a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid on KCl-induced contractions of rabbit tracheal smooth muscle, as well as the role of epithelium and endogenously produced nitric oxide and prostaglandins on these responses. L-Glutamate decreased KCI-induced contractions up to 30%. This effect was attenuated by epithelium removal, tetrodotoxin, methylene blue and indomethacin but not by NG-nitro-L-arginine methyl ester. While NMDA, AMPA and kainic acid had no effect, the combination of NMDA + kainic acid decreased KCI-induced contractions. These results suggest that, in rabbit trachea, L-glutamate has, at least in part, an epithelium-dependent effect mediated via prostaglandin formation and that the EAA receptors involved are non-classical.
Hatziefthimiou
Apostolia A
AA
Department of Physiology, Medical School, University of Thessaly, Larissa, Greece. axatzi@med.uth.gr
Gourgoulianis
Konstantinos I
KI
Molyvdas
Paschalis-Adam
PA
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000502:physiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D005260:Female; D018698:Glutamic Acid / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D011453:Prostaglandins / Q000502:physiology*; D011817:Rabbits; D014132:Trachea / Q000187:drug effects* / Q000502:physiology
D018690:Excitatory Amino Acid Agonists; D011453:Prostaglandins; D018698:Glutamic Acid; D011189:Potassium Chloride