Antisense knockdown of inducible nitric oxide synthase inhibits the relaxant effect of VIP in isolated smooth muscle cells of the mouse gastric fundus

• Published in: British journal of pharmacology Vol. 134; no. 2; pp. 425 - 433
• Main Authors: Dick, J M C, Van Molle, W, Libert, C, Lefebvre, R A
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2001; Nature Publishing
• Subjects: Amidines - pharmacology; Animals; antisense oligodeoxynucleotide; Arginine - pharmacology; Benzylamines - pharmacology; Biological and medical sciences; Carbachol - pharmacology; Cell Size - drug effects; Digestive system; DNA, Antisense - chemistry; DNA, Antisense - pharmacokinetics; DNA, Antisense - pharmacology; Enzyme Inhibitors - pharmacology; Female; Fluorescein-5-isothiocyanate - chemistry; Fundamental and applied biological sciences. Psychology; gastric fundus; Gastric Fundus - drug effects; Gastric Fundus - enzymology; Gastric Fundus - physiology; Glyburide - pharmacology; In Vitro Techniques; inducible nitric oxide synthase; Male; Medical sciences; Mice; Mice, Inbred C57BL; Muscle Relaxation - drug effects; Muscle, Smooth - cytology; Muscle, Smooth - drug effects; Muscle, Smooth - enzymology; Nitrates - metabolism; nitric oxide; Nitric Oxide Synthase - antagonists & inhibitors; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type II; Nitrites - metabolism; Nitroarginine - pharmacology; Pharmacology. Drug treatments; Pinacidil - pharmacology; Stomach; Tumor Necrosis Factor-alpha - pharmacology; Vasoactive Intestinal Peptide - pharmacology; vasoactive intestinal polypeptide; Vasodilator Agents - pharmacology; Vertebrates: digestive system; Stomach; Enzyme; Digestive system; Isozyme; Peptide hormone; Rodentia; Smooth muscle; Antisense oligonucleotide; Neuropeptide; In vitro; Nitric-oxide synthase; Muscular relaxation; Vertebrata; Gastrointestinal hormone; Mammalia; Mouse; Antispasmodic agent; Animal; Vasoactive intestinal peptide; Oxidoreductases; Mechanism of action
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0704262

Our previous results showed that the non‐selective nitric oxide synthase (NOS) inhibitor L‐NG‐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