title: [Role of Na(+)-K(+)-ATPase in lipopolysaccharide-induced cardiomyocyte hypertrophy in rats].
abstract: OBJECTIVE
  To explore the possible mechanism of lipopolysaccharide (LPS)-induced cardiomyocyte hypertrophy in rats.
  
  
  METHODS
  Neonatal rat cardiomyocytes cultured in vitro were stimulated with 100 µg/L LPS for 1, 4 or 8 h and scanned by atomic force microscopy (AFM) for measurement of the two-dimensional area, three-dimensional surface area and volume of each cell. The total proteins and Na(+)-K(+)-ATPase activity in the cardiomyocytes were determined. The same measurements were also carried out in neonatal rat cardiomyocyte cultures stimulated by 0.5 µmol/L ouabain for 8 h and the total protein levels were measured.
  
  
  RESULTS
  Following a 8-hour stimulation with LPS, the two-dimensional area, three-dimensional surface area and volume of the single cardiomyocyte became enlarged and the total cellular proteins increased significantly as compared with those in the normal control cells (P < 0.05). LPS treatment for 4 and 8 h resulted in significantly decreased activity of Na(+)-K(+)-ATPase in the cardiomyocytes (P < 0.05). In the cells treated with ouabain for 8 h, the two-dimensional area, three-dimensional surface area, volume of the single cardiomyocyte and the total cellular proteins increased significantly in comparison with the normal control group (P < 0.05).
  
  
  CONCLUSIONS
  LPS can result in cardiomyocyte hypertrophy in rats possibly in relation to lowered Na(+)-K(+)-ATPase activity in the cardiomyocytes after LPS exposure.
authors.affiliation: Center of Medical Experiment Teaching, Southern Medical University, Guangzhou 510515, China. yy000213@163.com
authors.forename: Li-qun
authors.initials: LQ
authors.lastname: Wang
authors.forename: Tang-ting
authors.initials: TT
authors.lastname: Chen
authors.forename: Ying-qian
authors.initials: YQ
authors.lastname: Cai
authors.forename: Xiang
authors.initials: X
authors.lastname: Xue
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhou
authors.forename: Chun-hua
authors.initials: CH
authors.lastname: Jin
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D049108:Cell Enlargement / Q000187:drug effects*; D002478:Cells, Cultured; D006984:Hypertrophy / Q000139:chemically induced; D008070:Lipopolysaccharides; D032383:Myocytes, Cardiac / Q000201:enzymology / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D000254:Sodium-Potassium-Exchanging ATPase