title: Down-regulation of basic fibroblast growth factor production from cartilage by excessive mechanical stress.
abstract: BACKGROUND
  We examined the effect of excessive stress on the production of basic fibroblast growth factor (bFGF) by bovine cartilage.
  
  
  METHODS
  Bovine articular carpal bone was harvested and cut into 1 cm thick slices horizontally. Continuous compressive stress (0, 2, 20 MPa) was loaded on the cartilage of the carpal bone using a stainless-steel cylinder with a diameter of 8 mm for 1 h. The slices were cultured immediately after compression, and the supernatant of the culture medium was collected for bFGF and nitric oxide (NO) measurement. Interleukin-4 (IL-4) or N(G)-monoethyl-L: -arginine (L: -NMEA) was added to the culture medium in some experiments.
  
  
  RESULTS
  Basic FGF production was significantly increased after 36 h of cultivation without mechanical stress (0.40 +/- 0.03 microg/ml). In contrast, the bFGF concentration was not increased by compressive stress of 20 MPa after 36 h of cultivation. An NO inhibitor, L: -NMEA, did not alter the effect of compressive stress on the production of bFGF. IL-4 reduced the production of bFGF by cartilage with or without mechanical stress.
  
  
  CONCLUSIONS
  Excessive stress on cartilage inhibits the production of bFGF in an NO-independent manner, and IL-4 plays an important role in the reduction of bFGF.
authors.affiliation: Department of Orthopaedic Surgery, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uesugi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Saito
mesh_terms: D000818:Animals; D050824:Carpal Joints / Q000033:anatomy & histology / Q000378:metabolism / Q000473:pathology; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D013314:Stress, Mechanical; D046509:Tissue Culture Techniques; D019323:omega-N-Methylarginine / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D016222:Fibroblast Growth Factor 2; D015847:Interleukin-4; D019323:omega-N-Methylarginine; D009569:Nitric Oxide