NG-nitro-L-arginine methyl ester inhibits the effect of an H3-histaminergic receptor agonist on NANC contraction in guinea-pig perfused bronchioles.
A role for nitric oxide in the H3-histaminergic agonist-induced inhibition of the non-adrenergic, non-cholinergic (NANC) contraction has been studied in guinea-pig perfused bronchioles. (R)-alpha-Methylhistamine ((R)-alpha-MeHA), an agonist for H3 receptors, inhibited the NANC contraction induced by electrical field stimulation. NG-Nitro-L-arginine methyl ester (L-NAME) (50 microM), an inhibitor of nitric oxide synthesis, blocked the effect of (R)-alpha-MeHA. The effect of L-NAME was reversed by L-arginine (50 microM). L-NAME, L-arginine or (R)-alpha-MeHA were without effect on exogenous substance P- or neurokinin A-induced contractile responses of the perfused bronchioles. These results show that an H3-agonist inhibited the release of neurotransmitters in NANC nerve endings of guinea-pig perfused bronchioles presumably by production of nitric oxide.
Laboratoire de Pharmacologie, UFR de Pharmacie, Limoges, France.
J L
JL
Burgaud
N
N
Oudart
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016084:Bronchoconstriction / Q000187:drug effects*; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D017442:Histamine Agonists / Q000494:pharmacology*; D008297:Male; D008761:Methylhistamines / Q000494:pharmacology*; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D018100:Receptors, Histamine H3 / Q000187:drug effects*
D017442:Histamine Agonists; D008761:Methylhistamines; D018100:Receptors, Histamine H3; D009569:Nitric Oxide; C069357:alpha-methylhistamine; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester