title: A comparison of the effects of pneumoperitoneum and laparotomy on natural killer cell mediated cytotoxicity and Walker tumor growth in Wistar rats.
abstract: BACKGROUND
  Surgical stress promotes impaired immunological function, which contributes to tumor growth. Natural killer activity (NKA) has a protective role in immunity to tumors. So, the aim of this experimental study was to assess tumor growth and (NKA) after pneumoperitoneum and laparotomy. METHODS; Sixty male Wistar rats were divided into three groups (anesthesia, CO2 pneumoperitoneum and laparotomy) plus ten controls. All experimental animals were inoculated subcutaneously with 8 x 105 Walker carcinosarcoma 256 cells. Animals were sacrificed on 1st(POD1) and 8th (POD8) postoperative day. Tumors were excised and weighed.
  
  
  RESULTS
  On POD1 all animals had diminished NKA when compared to controls; NKA after pneumoperitoneum was significantly greater than after laparotomy. On POD8 all animals, except after laparotomy, reached NKA at controls levels. Tumor weight was significantly greater after laparotomy when compared to pneumoperitoneum.
  
  
  CONCLUSIONS
  Pneumoperitoneum causes a less depressed NKA and less tumor growth when compared to laparotomy.
authors.affiliation: Surgical Anatomy, Sao Paulo University.
authors.forename: Paulo Emilio
authors.initials: PE
authors.lastname: Fuganti
authors.forename: Aldo Junqueira
authors.initials: AJ
authors.lastname: Rodrigues Júnior
authors.forename: Consuelo Junqueira
authors.initials: CJ
authors.lastname: Rodrigues
authors.forename: Maria
authors.initials: M
authors.lastname: Sato
mesh_terms: D000818:Animals; D002279:Carcinoma 256, Walker / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D018450:Disease Progression; D007111:Immunity, Cellular / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D007813:Laparotomy; D008297:Male; D010534:Peritoneal Neoplasms / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D011028:Pneumoperitoneum, Artificial; D011379:Prognosis; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical