title: The effects of arginase inhibitor on lung oxidative stress and inflammation caused by pneumoperitoneum in rats.
abstract: BACKGROUND
  Pneumoperitoneum-induced oxidative stress and organ injury are known to be associated with nitric oxide (NO) inactivation. Because arginase competes with NO synthase (NOS) for a common substrate, L-arginine, arginase inhibition may increase NO bioavailability. Therefore, we evaluated the ability of the arginase inhibitor, 2 (S)-amino-6-boronohexanoic acid (ABH), to attenuate pneumoperitoneum-induced decrease of NO bioavailability and lung injury.
  
  
  METHODS
  Thirty rats were randomly divided into the following groups: 1) the PP-ABH group received a subcutaneous injection of ABH (5 mg/kg) 1 h before induction of pneumoperitoneum (insufflation to intraperitoneal pressure of 15 mmHg for 60 min); 2) the PP group received saline by subcutaneous injection 1 h before induction of pneumoperitoneum; and 3) the control group received saline by subcutaneous injection before a sham procedure with no gas insufflation. After desufflation, blood was collected to determine levels of plasma nitrite, NOS, inflammatory cytokines, and malondialdehyde, a marker of oxidative stress. Lung tissue was obtained for histological evaluation.
  
  
  RESULTS
  We found that plasma nitrite levels were lower in the PP group and higher in the PP-ABH group, compared with controls (P <0.01 and P <0.05, respectively). In the PP group, endothelial NOS activity was decreased and inducible NOS activity was increased compared with the PP-ABH and control groups. Malondialdehyde levels increased 3-fold in the PP group and 2-fold in the PP-ABH group compared with controls. Tumor necrosis factor-α, interleukin-6, and interleukin-1ß levels were elevated in the PP group compared to the control group, but the increase in cytokine production was attenuated or blocked in the PP-ABH group. Lung injury scores were 4.8-fold higher in the PP group and 2-fold higher in the PP-ABH group compared with controls (P <0.001 and P <0.01, respectively).
  
  
  CONCLUSIONS
  Pneumoperitoneum decreases NO bioavailability and increases the inflammation cytokines, resulting in organ injuries. Inhibition of arginase activity could maintain NO bioavailability by attenuating pneumoperitoneum-induced changes in NOS activity. In addition, arginase inhibition attenuated the oxidative stress and inflammation and decreased the severity of lung injury caused by pneumoperitoneum.
  
  
  CONCLUSIONS
  By increasing NO bioavailability and suppressing oxidative stress and inflammation, pretreatment with an arginase inhibitor may protect against lung injury caused by pneumoperitoneum.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin Sun
authors.initials: JS
authors.lastname: Cho
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.|Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Oh
authors.affiliation: Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ok Soo
authors.initials: OS
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea. NSWKSJ@yuhs.ac.|Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea. NSWKSJ@yuhs.ac.
authors.forename: Sungwon
authors.initials: S
authors.lastname: Na
mesh_terms: D000614:Aminocaproates / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001119:Arginase / Q000037:antagonists & inhibitors*; D001896:Boron Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D007249:Inflammation / Q000209:etiology / Q000517:prevention & control*; D007279:Injections, Subcutaneous; D055370:Lung Injury / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D011027:Pneumoperitoneum / Q000150:complications* / Q000188:drug therapy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C121228:2-amino-6-boronohexanoic acid; D000614:Aminocaproates; D001896:Boron Compounds; D016207:Cytokines; D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D008315:Malondialdehyde; D001119:Arginase