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Antisense knockdown of inducible nitric oxide synthase inhibits the relaxant effect of VIP in isolated smooth muscle cells of the mouse gastric fundus
Author(s) -
Dick J M C,
Van Molle W,
Libert C,
Lefebvre R A
Publication year - 2001
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0704262
Subject(s) - nitric oxide synthase , gene knockdown , gastric fundus , smooth muscle , nitric oxide , chemistry , pharmacology , neuronal nitric oxide synthase , biochemistry , biology , endocrinology , stomach , apoptosis
Our previous results showed that the non‐selective nitric oxide synthase (NOS) inhibitor L ‐N G ‐nitroarginine ( L ‐NOARG) and the selective inducible NOS (iNOS) inhibitor N‐(3‐(acetaminomethyl)‐benzyl)acetamidine (1400W) inhibited the relaxant effect of vasoactive intestinal polypeptide (VIP) in isolated smooth muscle cells of the mouse gastric fundus, suggesting the involvement of iNOS. The identity of the NOS isoform involved in the VIP‐induced relaxation in isolated smooth muscle cells of the mouse gastric fundus was now further investigated by use of antisense oligodeoxynucleotides (aODNs) to iNOS. Incubation of isolated smooth muscle cells with fluorescein isothiocyanate (FITC)‐labelled aODNs showed that nuclear accumulation occurs quickly and reaches saturation after 60 min. The in vivo intravenous administration of aODNs to iNOS, 24 and 12 h before murine tumour necrosis factor alpha (mTNFα) challenge, significantly reduced the nitrite levels induced by the mTNFα challenge. Intravenous administration of aODNs to iNOS in mice, 24 and 12 h before isolation of the gastric smooth muscle cells, decreased the inhibitory effect of the NOS inhibitors L ‐NOARG and 1400W on the relaxant effect of VIP, whereas neither saline nor sODNs had any influence. Preincubation of the isolated smooth muscle cells with aODNs almost abolished the inhibitory effect of L ‐NOARG and 1400W on the VIP‐induced relaxation, whereas sODNs failed. These results illustrate that the inhibitory effect of NOS inhibitors in isolated smooth muscle cells of the mouse gastric fundus is due to inactivation of iNOS. iNOS, probably induced by the isolation procedure of the smooth muscle cells, seems involved in the relaxant effect of VIP in isolated gastric smooth muscle cells.British Journal of Pharmacology (2001) 134 , 425–433; doi: 10.1038/sj.bjp.0704262