Collagenase: an experimental study of intervertebral disc dissolution.

This study reports the use of a purified form of the enzyme collagenase (Nucleolysin) to effect dissolution of the normal nucleus pulposus in a series of dogs and monkeys. A consistent dissolution effect has been observed. The toxicity of the enzyme to surrounding local tissues has been studied in the same species with an indication of safety in all areas other than intrathecal administration. A margin of safety in intrathecal administration between the effective dose and toxic dose has been suggested in the monkey. Mice LD50 studies and systemic toxicity studies in dogs show a satisfactory margin of safety for this enzyme. Guinea pig studies show no significant antigenicity.