title: Increased production of nitric oxide by neutrophils and monocytes from cirrhotic patients with ascites and hyperdynamic circulation.
abstract: An increased release of nitric oxide (NO), a powerful vasodilating agent, has been proposed to play a role in the pathogenesis of vasodilation and hyperdynamic circulation associated with advanced cirrhosis. We evaluated NO synthase (NOS) activity in peripheral leukocytes of 12 cirrhotic patients and 9 healthy subjects together with plasma endotoxin levels and systemic hemodynamic (by a noninvasive echocardiographic method). NOS activity was evaluated by (1) measuring the capacity of isolated polymorphonuclear cells (PMNs) and monocytes to convert [3H]arginine to [3H]citrulline; (2) measuring the ability of neutrophils and monocytes to inhibit thrombin-induced platelet aggregation and to increase guanosine 3'-5'-cyclic monophosphate content in coincubated platelets, an expression of NO release from these cells. Both neutrophils and monocytes from cirrhotic patients produced significantly higher amounts of [3H]citrulline than cells obtained from healthy subjects (P < .001 and P < .02 for neutrophils and monocytes, respectively) and were more effective than control cells in inhibiting platelet aggregation (P < .05 and P < .001, respectively for 2 x 10(6) cells) and in increasing guanosine 3'-5'-cyclic monophosphate content in coincubated platelets (P < .05 and P < .001, respectively). The anti-aggregating activity expressed by leukocytes has a pharmacological profile similar to that described for NO, because it increased after addition of superoxide dismutase, a superoxide anion scavenger, and markedly decreased after inhibition of nitric oxide synthesis with NG-monomethyl-L-arginine (L-NMMA) and NG-nitro-L-arginine-methyl ester (L-NAME). Cirrhotic patients had significantly higher plasma endotoxin levels (P < .001) and cardiac index (P < .01) when compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000368:Aged; D001120:Arginine / Q000378:metabolism; D001201:Ascites; D001792:Blood Platelets / Q000378:metabolism; D002956:Citrulline / Q000378:metabolism; D004791:Enzyme Inhibitors; D005260:Female; D006157:Guanosine Monophosphate / Q000097:blood; D006339:Heart Rate; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008103:Liver Cirrhosis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D009569:Nitric Oxide / Q000097:blood* / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000097:blood; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D013318:Stroke Volume; D014316:Tritium
chemical_list: D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; D010975:Platelet Aggregation Inhibitors; D014316:Tritium; D002956:Citrulline; D009569:Nitric Oxide; D006157:Guanosine Monophosphate; D001120:Arginine; D019001:Nitric Oxide Synthase