In Brief:
Three enzymes, MMP-3, ADAMTS-4, and HTRA1, were injected into bovine in vitro organ culture for 8 days. Metabolic cell activity was significantly reduced in discs injected with ADAMTS-4. No significant changes were observed in tissue gene expression, collagen content, or morphology, although HTRA1 did induce a loss in disc height that positively correlated with changes in GAG/DNA content.
