title: [Effects of pulsed ultrasound and pulsed electromagnetic field on the extracellular matrix secretion of rat bone marrow mesenchymal stem cell pellets in chondrogenesis].
abstract: OBJECTIVE
  To study the effects of pulsed ultrasound (PUS) and pulsed electromagnetic fields (PEMF) on the secretion of extracellular matrix from a culture complex during in vitro chondrogenesis.
  
  
  METHODS
  All the rat bone marrow mesen- chymal stem cell pellets were cultured in achondrogenic medium. Different intensities of PUS (100, 150, and 200 mW · cm⁻²) and PEMF (1, 2, and 5 mT) were applied to the cell pellets for 2 weeks. Group N was cultured without PUS and PEMF stimu- lation as control. The culture medium was collected after 2 weeks of culture. Enzyme-linked immunosorbent assay (ELISA) was used to detect the type of collagen and glycosaminoglycan (GAG) in the culture medium.
  
  
  RESULTS
  PUS increased the secreting-type collagen and GAG from cell pellets compared with group N (P < 0.05), whereas there was no difference in different intensities (P > 0.05). PEMF had no significant effect on the secretion of the type of collagen (P > 0.05). A PEMF of 1 mT had no significant effect on the secretion of GAG (P > 0.05). A PEMF 2 and 5 mT decreased the secretion of GAG (P < 0.05).
  
  
  CONCLUSIONS
  To prevent the secretary of extracellular matrix may play a role in chondrogenic effect of PEMF.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhi
authors.forename: Tang
authors.initials: T
authors.lastname: Na
authors.forename: Wang
authors.initials: W
authors.lastname: Jue
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhihe
authors.forename: Tan
authors.initials: T
authors.lastname: Lijun
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000528:radiation effects*; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000528:radiation effects*; D004574:Electromagnetic Fields; D005109:Extracellular Matrix; D006025:Glycosaminoglycans; D006412:Hematopoietic Stem Cells; D059630:Mesenchymal Stem Cells / Q000528:radiation effects*; D051381:Rats; D000069453:Ultrasonic Waves
chemical_list: D006025:Glycosaminoglycans