title: Ethylene diamine tetraacetic acid-induced colonic crypt cell proliferation in rats.
abstract: OBJECTIVE
  To investigate the effect of ethylene diamine tetraacetic acid (EDTA) on proliferation of rat colonic cells.
  
  
  METHODS
  EDTA was administered into Wistar rats, carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats was studied with immunohistochemistry.
  
  
  RESULTS
  Marked regional differences in cell proliferation were found in all groups. In EDTA-treated animals, total labelling indexes in both proximal (10.00 +/- 0.44 vs 7.20 +/- 0.45) and distal (11.05 +/- 0.45 vs 8.65 +/- 0.34) colon and proliferative zone size (21.67 +/- 1.13 vs 16.75 +/- 1.45, 27.73 +/- 1.46 vs 21.74 +/- 1.07) were significantly higher than that in normal controls (P<0.05) and lower than that in DMH group (10.00 +/- 0.44 vs 11.54 +/- 0.45, 11.05 +/- 0.45 vs 13.13 +/- 0.46, 21.67 +/- 1.13 vs 35.52 +/- 1.58, 27.73 +/- 1.46 vs 39.61 +/- 1.32, P<0.05). Cumulative frequency distributions showed a shift of the EDTA distal curve to the right (P<0.05) while the EDTA proximal curve did not change compared to normal controls. Despite the changes of proliferative parameters, tumours did not develop in EDTA treated animals.
  
  
  CONCLUSIONS
  Hyperproliferation appears to be more easily induced by EDTA in distal colon than in proximal colon. Hyperproliferation may need to exceed a threshold to develop colonic tumours. EDTA may work as a co-factor in colonic tumorigenesis.
authors.affiliation: Department of Surgery, First Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China. qyma0@163.com
authors.forename: Qing-Yong
authors.initials: QY
authors.lastname: Ma
authors.forename: Kate E
authors.initials: KE
authors.lastname: Williamson
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Rowlands
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000473:pathology; D000236:Adenoma / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D001973:Bromodeoxyuridine; D002455:Cell Division / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology*; D003106:Colon / Q000166:cytology* / Q000187:drug effects*; D015179:Colorectal Neoplasms / Q000139:chemically induced* / Q000473:pathology; D004195:Disease Models, Animal; D004492:Edetic Acid / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002614:Chelating Agents; D004492:Edetic Acid; D001973:Bromodeoxyuridine