title: Nitric oxide-releasing oxatriazole derivatives inhibit human lymphocyte proliferation by a cyclic GMP-independent mechanism.
abstract: Two novel nitric oxide (NO)-releasing oxatriazole derivatives, GEA 3162 and GEA 3175, and an earlier known NO donor, S-nitroso-N-acetylpenicillamine (SNAP), inhibited cell proliferation and enhanced cGMP production in a concentration-dependent manner in human lymphocytes activated by lectin mitogen concanavalin A (ConA). The possible mediator role of cGMP in the antiproliferative action of NO donors was tested by pharmacological means. An inhibitor of guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one, inhibited NO donor-induced cGMP production, whereas the antiproliferative action of NO donors remained unaltered. Phosphodiesterase inhibitors zaprinast and 3-isobutyl-1-methylxanthine potentiated and prolonged NO donor-induced increase in the concentrations of cGMP but did not enhance the antiproliferative action of NO donors. In addition, two analogs of cGMP, 8-bromo-cGMP and a more cell-permeable compound, 8-p-chlorophenylthio-cGMP, did not inhibit ConA-stimulated lymphocyte proliferation when used in concentrations of up to 300 microM. At millimolar concentrations, 8-bromo-cGMP had a moderate inhibitory action. These results suggest that nitric oxide-releasing oxatriazole derivatives inhibit proliferative responses in human lymphocytes by a cGMP-independent manner.
authors.affiliation: University of Tampere, Medical School, Department of Pharmacological Sciences, Finland.
authors.forename: O
authors.initials: O
authors.lastname: Kosonen
authors.forename: H
authors.initials: H
authors.lastname: Kankaanranta
authors.forename: M
authors.initials: M
authors.lastname: Lähde
authors.forename: P
authors.initials: P
authors.lastname: Vuorinen
authors.forename: P
authors.initials: P
authors.lastname: Ylitalo
authors.forename: E
authors.initials: E
authors.lastname: Moilanen
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D009569:Nitric Oxide / Q000502:physiology*; D014230:Triazoles / Q000494:pharmacology*
chemical_list: C093084:GEA 3175; D014230:Triazoles; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; C082874:GEA 3162; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D015056:1-Methyl-3-isobutylxanthine