title: Isolation-stress increases small intestinal sensitivity to chemotherapy in rats.
abstract: OBJECTIVE
  Severe gastrointestinal damage often complicates the use of chemotherapeutic agents such as methotrexate for anticancer treatment. Psychologic stress is known to be detrimental to normal intestinal physiology. We set out to determine if psychologic stress adds to the intestinal damage provoked by chemotherapy.
  
  
  METHODS
  Rats were treated with various doses of methotrexate and housed either alone, which induces mental stress, or maintained in groups of 3 animals. Treatment was evaluated by (immuno)histologic parameters.
  
  
  RESULTS
  Epithelial crypt damage, increased lysozyme expression, decreased sucrase-isomaltase and sodium/glucose transporter 1 expression, and pathologic changes in mucin and trefoil factor protein expression could be prevented by avoiding isolation. Enhanced cytotoxicity of methotrexate through isolation was about 2-fold and involved an augmented inhibition of proliferation, increased epithelial apoptosis, increased villus damage, and delayed recovery. We could not identify a role for mucosal mast cells in the increased epithelial damage under isolated conditions.
  
  
  CONCLUSIONS
  The clear beneficial effects of avoiding mental stress on the protection of the intestinal epithelium during cytostatic drug-treatment may be an important element for the treatment of cancer patients.
authors.affiliation: Pediatric Gastroenterology & Nutrition, Laboratory of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Melissa
authors.initials: M
authors.lastname: Verburg
authors.forename: Ingrid B
authors.initials: IB
authors.lastname: Renes
authors.forename: Alexandra W C
authors.initials: AW
authors.lastname: Einerhand
authors.forename: Hans A
authors.initials: HA
authors.lastname: Büller
authors.forename: Jan
authors.initials: J
authors.lastname: Dekker
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects*; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007421:Intestine, Small / Q000187:drug effects*; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage / Q000009:adverse effects*; D008871:Microvilli / Q000187:drug effects / Q000473:pathology; D009113:Muramidase / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D012934:Social Isolation; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D000964:Antimetabolites, Antineoplastic; D011506:Proteins; D009113:Muramidase; D008727:Methotrexate