title: Melatonin modulates mesenteric blood flow and TNFalpha concentrations after lipopolysaccharide challenge.
abstract: OBJECTIVE
  To investigate the effect of various doses of melatonin on reduction in mesenteric blood flow (MBF) and increase in tumour necrosis factor alpha (TNFalpha) concentration caused by injection of lipopolysaccharide (LPS).
  
  
  METHODS
  University Hospital, Turkey.
  
  
  METHODS
  Open experimental study.
  
  
  METHODS
  59 Swiss albino mice.
  
  
  METHODS
  Animals were injected with melatonin solvent or 1, 10, 100, or 500 mg/kg melatonin. Ten minutes later control animals were injected with saline, and the experimental group with LPS.
  
  
  METHODS
  Mesenteric blood flow and serum TNFalpha concentration.
  
  
  RESULTS
  In control animals, 100 and 500 mg/kg melatonin reduced MBF. LPS reduced MBF in solvent, 1, and 10 mg/kg melatonin groups. The concentration of TNFalpha was considerably increased in the mice given LPS. Melatonin reduced this response significantly.
  
  
  CONCLUSIONS
  In high doses melatonin directly reduces MBF. It has no protective effect on the LPS-induced decrease in MBF. In lower doses it blocks, but at higher doses reduces, LPS-induced TNFalpha production.
authors.affiliation: Department of General Surgery, University of Hacettepe, Faculty of Medicine, Ankara, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Baykal
authors.forename: A B
authors.initials: AB
authors.lastname: Iskit
authors.forename: E
authors.initials: E
authors.lastname: Hamaloglu
authors.forename: M O
authors.initials: MO
authors.lastname: Guc
authors.forename: G
authors.initials: G
authors.lastname: Hascelik
authors.forename: I
authors.initials: I
authors.lastname: Sayek
mesh_terms: D000818:Animals; D005260:Female; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D011897:Random Allocation; D012772:Shock, Septic / Q000097:blood; D012997:Solvents / Q000494:pharmacology; D013152:Splanchnic Circulation / Q000187:drug effects* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D012997:Solvents; D014409:Tumor Necrosis Factor-alpha; D008550:Melatonin