title: Value and limitations of using the bovine tail as a model for the human lumbar spine.
abstract: METHODS
  The contents of DNA, proteoglycan, type II collagen, and denatured type II collagen in the bovine coccygeal intervertebral discs were examined in situ in relation to disc level, age, and tissue region.
  
  
  OBJECTIVE
  To determine whether bovine coccygeal discs are a suitable model to study human lumbar discs.
  
  
  BACKGROUND
  Bovine coccygeal discs have been suggested as a suitable alternative model because they are readily available, in contrast to human discs, and represent a common source of tissue in the disc field. However, it is not known whether the changes in matrix contents in bovine coccygeal discs are similar to those found in the human lumbar spine.
  
  
  METHODS
  Intervertebral discs from bovine tails were dissected into the nucleus pulposus (NP) and anulus fibrosus (AF). Tissues were weighed and analyzed for matrix contents using specific assays.
  
  
  RESULTS
  Similar to water content, the proteoglycan content was higher in the NP than in the AF. Water content of the bovine NP did not change with age, unlike the proteoglycan content, which decreased. type II collagen content was higher in the NP than in the AF, and both did not change overall significantly with age. The percent of denatured type II collagen decreased with age only in the NP. The DNA content did not vary with age in the AF and in the NP.
  
  
  CONCLUSIONS
  Differences in matrix contents exist between the bovine coccygeal discs and the human lumbar spine. Thus, caution must be exercised when using the bovine tail as a model for the human lumbar spine in biochemical studies.
authors.affiliation: Division of Orthopaedic Surgery, Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Caroline N
authors.initials: CN
authors.lastname: Demers
authors.forename: John
authors.initials: J
authors.lastname: Antoniou
authors.forename: Fackson
authors.initials: F
authors.lastname: Mwale
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D002417:Cattle; D003050:Coccyx / Q000737:chemistry / Q000378:metabolism*; D024043:Collagen Type II / Q000032:analysis / Q000378:metabolism; D004247:DNA / Q000032:analysis / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007403:Intervertebral Disc / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D011489:Protein Denaturation; D011509:Proteoglycans / Q000032:analysis / Q000378:metabolism; D013045:Species Specificity; D013623:Tail; D014867:Water / Q000032:analysis / Q000378:metabolism
chemical_list: D024043:Collagen Type II; D011509:Proteoglycans; D014867:Water; D004247:DNA