TY - JOUR
T1 - Production of Collagenase and Tissue Inhibitor of Metal loproteinases (TIMP) by Rat Growth Plates in Culture
AU - Dean, David D.
AU - Muniz, Ofelia E.
AU - Woessner, J. F.
AU - Howell, David S.
N1 - Funding Information:
The authors would like to express their appreciation for the expert technical assistance provided by Ms. Agueda Agundez, Ms. Maria Elena Madan, Ms. Sara Morales, Ms. Carolyn Taplin and Ms. Ivette Rodriquez. Supported by National Institutes of Health grants AR-08662 and AR-16940 and a merit review grant from the U.S. Veterans Administration.
PY - 1990
Y1 - 1990
N2 - Growth plate cartilage from normal and vitamin D-phosphate deficient (-VDP) rats was cultured to study the production of collagenase and tissue inhibitor of metalloproteinases (TIMP) in vitro. All tissues secreted latent collagenase into the medium at a constant rate during the 5 days in culture. Microdissected-VDP growth plates, containing predominately hyper- trophic cells, released up to 8-fold more collagenase into the medium than either intact -VDP or normal growth plates. TIMP was also secreted during the culture, but its rate of production was not as dependent on tissue type as collagenase. The tissue level of collagenase and TIMP before culture was compared with that found in conditioned medium and remnant tissue after culture. During the 5 day culture period microdis- sected - VDP growth plates, containing predominately hypertrophic cells, produced 3-times more collagenase/μg DNA over the starting level than either intact -VDP or normal growth plates. TIMP was never found in tissues after they had been cultured, but was present in all tissues before culture except those containing predominately hypertrophic cells. The amount of TIMP required to block collagenase was calculated. Growth plates in culture produced enough TIMP to block all collagenase found in the medium and remnant tissue, while extracts of uncultured intact -VDP growth plates, and those divided to contain hypertrophic cells, had an excess of collagenase over TIMP. The results suggest that hypertrophic cells produce far more collagenase than other cells in the growth plate, but all cell types have about the same capacity to synthesize TIMP. As a result, increased collagenase synthesis by hypertrophic cells may surpass increases in TIMP synthesis and lead to collagen removal. This would allow for thinning of the longitudinal septa and expansion of the hypertrophic cells.
AB - Growth plate cartilage from normal and vitamin D-phosphate deficient (-VDP) rats was cultured to study the production of collagenase and tissue inhibitor of metalloproteinases (TIMP) in vitro. All tissues secreted latent collagenase into the medium at a constant rate during the 5 days in culture. Microdissected-VDP growth plates, containing predominately hyper- trophic cells, released up to 8-fold more collagenase into the medium than either intact -VDP or normal growth plates. TIMP was also secreted during the culture, but its rate of production was not as dependent on tissue type as collagenase. The tissue level of collagenase and TIMP before culture was compared with that found in conditioned medium and remnant tissue after culture. During the 5 day culture period microdis- sected - VDP growth plates, containing predominately hypertrophic cells, produced 3-times more collagenase/μg DNA over the starting level than either intact -VDP or normal growth plates. TIMP was never found in tissues after they had been cultured, but was present in all tissues before culture except those containing predominately hypertrophic cells. The amount of TIMP required to block collagenase was calculated. Growth plates in culture produced enough TIMP to block all collagenase found in the medium and remnant tissue, while extracts of uncultured intact -VDP growth plates, and those divided to contain hypertrophic cells, had an excess of collagenase over TIMP. The results suggest that hypertrophic cells produce far more collagenase than other cells in the growth plate, but all cell types have about the same capacity to synthesize TIMP. As a result, increased collagenase synthesis by hypertrophic cells may surpass increases in TIMP synthesis and lead to collagen removal. This would allow for thinning of the longitudinal septa and expansion of the hypertrophic cells.
KW - chondrocyte hypertrophy
KW - collagenase
KW - growth plate cartilage
KW - tissue inhibitor of metalloproteinases (TIMP)
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U2 - 10.1016/S0934-8832(11)80188-5
DO - 10.1016/S0934-8832(11)80188-5
M3 - Article
C2 - 1964714
AN - SCOPUS:0025116462
SN - 0934-8832
VL - 10
SP - 320
EP - 330
JO - Matrix
JF - Matrix
IS - 5
ER -