title: Calpain inhibition by cerebrospinal fluid and effects of calpain on intrathecal nerve tissue.
abstract: METHODS
  The effects of calpain on intrathecal nerve tissue in the rabbit were investigated.
  
  
  OBJECTIVE
  To evaluate the chemonucleolytic side effect of calpain on nerve tissue in the event of accidental intrathecal calpain injection.
  
  
  BACKGROUND
  Calpain has a degradative effect on proteoglycans, and as previously shown, it is associated with chemonucleolytic action in the rabbit. However, its effect on nerve tissue in the event of accidental intrathecal injection is not clear.
  
  
  METHODS
  The inhibitory activity of cerebrospinal fluid against calpain was measured in human cerebrospinal fluid using mu-calpain, and in different cerebrospinal fluid fractions separated by molecular filtration. The presence of the endogenous calpain inhibitor, calpastatin, in human cerebrospinal fluid was examined by Western blotting with anticalpastatin antibody. After intrathecal application of calpain in rabbits, the spinal cord nerve tissue was examined by light microscopy.
  
  
  RESULTS
  Cerebrospinal fluid inhibited the enzyme reaction of calpain at its normal concentration. Immunoblotting with anticalpastatin antibody did not yield positive staining. After the intrathecal application of calpain, there was no evidence of degeneration in the nerve tissue of the spinal cord.
  
  
  CONCLUSIONS
  This study suggests that in the event of accidental intrathecal injection of calpain for chemonucleolysis, the enzyme activity of calpain will be neutralized by cerebrospinal fluid, and the calpain should not cause unwanted side effects in chemonucleolysis.
authors: Departments of Orthopaedic Surgery and; Biochemistry, Gifu University School of Medicine, Gifu, Japan.
authors: Hirotaka
authors: H
authors: Kodama
authors: Katsuji
authors: K
authors: Shimizu
authors: Yoshiko
authors: Y
authors: Banno
authors: Yuka
authors: Y
authors: Nonomura
authors: Hidefumi
authors: H
authors: Oshita
authors: Atsushi
authors: A
authors: Akaike
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D002555:Cerebrospinal Fluid / Q000737:chemistry / Q000502:physiology*; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009417:Nerve Tissue / Q000187:drug effects* / Q000473:pathology; D011817:Rabbits; D013116:Spinal Cord / Q000187:drug effects / Q000473:pathology
chemical_list: D002154:Calpain