title: In vitro ¹⁴C-labeled amino acid uptake changes and surface abnormalities in the colon after 1,2-dimethylhydrazine-induced experimental carcinogenesis: protection by zinc.
abstract: The present study explored the regulatory role of zinc on the in vitro uptake of ¹⁴C-glucose and ¹⁴C-labeled amino acids and on colonic surface abnormalities after 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. Rats were segregated into four groups: control, DMH-treated, zinc-treated, and DMH + zinc-treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 16 weeks. Zinc (in the form of zinc sulfate) was given to rats at a dose level of 227 mg/L in their drinking water. DMH treatment caused a significant decrease in the activities of disaccharidases (sucrase, lactase, and maltase), but a significant increase in the activity of alkaline phosphatase. In vitro uptake of ¹⁴C-D-glucose and the amino acids ¹⁴C-glycine, ¹⁴C-alanine, ¹⁴C-lysine, and ¹⁴C-leucine were significantly higher in the colons of DMH-treated rats. Zinc supplementation of DMH-treated rats resulted in regulating the altered intestinal enzyme activities and in vitro uptake of ¹⁴C-amino acids and ¹⁴C-glucose. Scanning electron microscopy revealed drastic alterations in the colon surface morphology after DMH treatment, which were restored after zinc supplementation. Our results confirm a beneficial effect of zinc against DMH-induced alterations in the colons of rats.
authors.affiliation: Department of Biophysics and Centre of Nuclear Medicine, Institute for Emerging Areas in Science and Technology, Panjab University, Chandigarh, India.
authors.forename: Vijayta Dani
authors.initials: VD
authors.lastname: Chadha
authors.forename: Devinder K
authors.initials: DK
authors.lastname: Dhawan
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000494:pharmacology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002250:Carbon Radioisotopes; D003106:Colon / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D004186:Disaccharidases / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D051381:Rats; D017207:Rats, Sprague-Dawley; D015032:Zinc / Q000378:metabolism; D019287:Zinc Sulfate / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000596:Amino Acids; D016588:Anticarcinogenic Agents; D002250:Carbon Radioisotopes; D019287:Zinc Sulfate; D000469:Alkaline Phosphatase; D004186:Disaccharidases; D019813:1,2-Dimethylhydrazine; D015032:Zinc