title: NG-methyl-L-arginine, an inhibitor of nitric oxide synthase, reverses interleukin-2-induced hypotension.
abstract: OBJECTIVE
  To evaluate the role of NG-methyl-L-arginine as a modulator of the hyperdynamic shock induced by the administration of interleukin-2 (IL-2).
  
  
  METHODS
  A prospective, pilot clinical study.
  
  
  METHODS
  Intensive care unit of a tertiary care center.
  
  
  METHODS
  Three sequential patients with metastatic renal cell carcinoma who developed hypotension during their first course of treatment with high-dose IL-2 (18 x 10(6) IU/m2/day by continuous infusion for 5 days).
  
  
  METHODS
  Upon developing hypotension during their subsequent therapy with IL-2, patients were administered 12 mg/kg of NG-methyl-L-arginine. Thereafter, a dose of 4 mg/kg was given every 4 hrs, as needed, to maintain the systolic blood pressure above 100 mm Hg.
  
  
  RESULTS
  Invasive hemodynamic monitoring was instituted before the initiation of treatment with IL-2. Differences noted before, and 15 mins after, the administration of NG-methyl-L-arginine were analyzed using the paired t-test. NG-methyl-L-arginine (12 mg/kg) induced a significant antihypotensive effect (mean blood pressure increased from 87 +/- 4 to 121 +/- 7 mm Hg), accompanied by an increase of the systemic vascular resistance (549 +/- 51 to 860 +/- 167 dyne.sec/cm5) and pulmonary vascular resistance (81 +/- 16 to 117 +/- 29 dyne.sec/cm5). A decrease in the cardiac index was also documented (4.5 +/- 0.5 to 3.6 +/- 0.3 L/min/m2). No significant changes in pulmonary artery occlusion and central venous pressures were observed. Maintenance doses of 4 mg/kg of NG-methyl-L-arginine induced similar hemodynamic results, although the duration of the antihypotensive effect of NG-methyl-L-arginine decreased with sequential doses.
  
  
  CONCLUSIONS
  The hemodynamic effects induced by IL-2 administration are reversed by NG-methyl-L-arginine, a nitric oxide synthesis inhibitor. These results provide evidence for the biological activity of NG-methyl-L-arginine when administered alone to hypotensive patients. While no adverse effects were observed in this preliminary study, issues of toxicity and effectiveness need to be defined further in formal clinical trials. NG-methyl-L-arginine may play a therapeutic role in the modulation of the extreme vasodilation induced by cytokine administration or in septic shock.
authors.affiliation: Department of Genitourinary Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
authors.forename: R G
authors.initials: RG
authors.lastname: Kilbourn
authors.forename: G A
authors.initials: GA
authors.lastname: Fonseca
authors.forename: O W
authors.initials: OW
authors.lastname: Griffith
authors.forename: M
authors.initials: M
authors.lastname: Ewer
authors.forename: K
authors.initials: K
authors.lastname: Price
authors.forename: A
authors.initials: A
authors.lastname: Striegel
authors.forename: E
authors.initials: E
authors.lastname: Jones
authors.forename: C J
authors.initials: CJ
authors.lastname: Logothetis
mesh_terms: D000328:Adult; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000556:secondary; D004334:Drug Administration Schedule; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D007376:Interleukin-2 / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D010865:Pilot Projects; D011446:Prospective Studies; D019323:omega-N-Methylarginine
chemical_list: D007376:Interleukin-2; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine