TY - JOUR T1 - Down-Regulation of Inducible Nitric-Oxide Synthase (NOS-2) During Parasite-Induced Gut Inflammation: A Path to Identify a Selective NOS-2 Inhibitor JF - Molecular Pharmacology JO - Mol Pharmacol SP - 939 LP - 947 DO - 10.1124/mol.59.4.939 VL - 59 IS - 4 AU - Ka Bian AU - Yael Harari AU - Meng Zhong AU - Mildred Lai AU - Gilbert Castro AU - Norman Weisbrodt AU - Ferid Murad Y1 - 2001/04/01 UR - http://molpharm.aspetjournals.org/content/59/4/939.abstract N2 - Nitric oxide (NO) possesses potent anti-inflammatory properties; however, an over-production of NO will promote inflammation and induce cell and tissue dysfunction. Thus, the ability to precisely regulate NO production could prove beneficial in controlling damage. In this study, advantage was taken of the well characterized inflammatory response caused by an intestinal parasite, Trichinella spiralis, to study the relationship between intestinal inflammation and the regulation of nitric oxide synthase-type 2 (NOS-2) expression. Our study revealed that a specific gut inflammatory reaction results in inhibition of NOS-2 expression. Characteristics of this inhibition are: 1) local jejunal inflammation induced by T. spiralissystemically inhibits NOS-2 gene transcription, protein expression, and enzyme activity; 2) the inhibition blunts endotoxin-stimulated NOS-2 expression; 3) the inhibition does not extend to the expression of other isoforms of NOS, to paxillin, a housekeeper protein, or to cyclooxygenase-2, another protein induced by proinflammatory cytokines; 4) the inhibition is unlikely related to the formation of specific anti-parasite antibodies; and 5) the inhibition may involve substances other than stress-induced corticosteroids. Elucidation of such potent endogenous NOS-2 down-regulatory mechanisms could lead to the development of new strategies for the therapy of inflammatory conditions characterized by the overproduction of NO. ER -