title: Interplay between nitric oxide and vasoactive intestinal polypeptide in the pig gastric fundus smooth muscle.
abstract: The aim of this study was to investigate the exact mechanism of interaction between nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) as inhibitory non-adrenergic non-cholinergic (NANC) neurotransmitters in isolated smooth muscle cells and smooth muscle strips of the pig gastric fundus. In isolated smooth muscle cells, the maximal relaxant effect of VIP (10(-9) M) was inhibited by 94% by the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine (L-NA, 10(-4) M) and by 85% by the inducible NOS (iNOS)-selective inhibitor N-(3-(aminomethyl)-benzyl)acetamide (1400W; 10(-6) M). The relaxant effect of VIP was reduced by more than 70% by the guanylyl cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ; 10(-6) M), the glucocorticoid dexamethasone (10(-5) M) and three protein kinase A inhibitors: (R)-p-cyclic adenosine-3', 5'-monophosphothioate ((R)-p-cAMPS; 10(-6) M), ¿(8R,9S, 11S)-(-)-9-hydroxy-9-n-hexylester-8-methyl-2,3,9,10-tetrahydro-8, 11-epoxy-1H,8H,11H-2,7b,11a-triazadibenzo[a, g]cycloocta[cde]-trin-den-1-one¿ (KT5720; 10(-6) M) and N-(2-(p-bromo-cinnamylamino)ethyl))-5-isoquinoline sulfonamide dihydrochloride (H-89; 10(-5) M). In contrast, no influence of the NOS inhibitors, ODQ, dexamethasone, nor the protein kinase A inhibitors could be observed on the relaxant effect of VIP in smooth muscle strips. These data demonstrate that the experimental method completely changes the influence of NOS inhibitors on the relaxant effect of VIP in the pig gastric fundus. The isolation procedure of the smooth muscle cells might induce iNOS that can be activated by VIP.
authors.affiliation: Heymans Institute of Pharmacology, Ghent University Medical School, De Pintelaan 185, B-9000, Ghent, Belgium.
authors.forename: J M
authors.initials: JM
authors.lastname: Dick
authors.forename: R A
authors.initials: RA
authors.lastname: Lefebvre
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000578:Amidines / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001596:Benzylamines / Q000494:pharmacology; D002227:Carbazoles; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005748:Gastric Fundus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II; D019335:Nitroarginine / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011758:Pyrroles / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D013449:Sulfonamides; D013552:Swine; D013873:Thionucleotides / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D000067956:Adenylyl Cyclase Inhibitors; D000578:Amidines; D001596:Benzylamines; D002227:Carbazoles; D004791:Enzyme Inhibitors; D007211:Indoles; D007546:Isoquinolines; C104820:N-(3-(aminomethyl)benzyl)acetamidine; D010069:Oxadiazoles; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D011810:Quinoxalines; D013449:Sulfonamides; D013873:Thionucleotides; C017759:9-(tetrahydro-2-furyl)-adenine; D005576:Colforsin; D019335:Nitroarginine; C016957:adenosine-3',5'-cyclic phosphorothioate; D009569:Nitric Oxide; D014660:Vasoactive Intestinal Peptide; C057416:KT 5720; D003907:Dexamethasone; D001120:Arginine; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D000225:Adenine; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide