# RECOVERY OF INTERVERTEBRAL DISC AFTER ENZYME TREATMENT

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 1988 · $119,537

## Abstract

The main hypothesis of the proposal is that after insult by an exogenous
protease, such as chymopapain or alternate enzymes such as protease K or
pronase, the nucleus pulposus has the ability to regenerate.  This
hypothesis will be tested by examining biochemical and histologic evidence
or recovery using as a model system, dog intervertebral disc injected with
protease (0.2 to 1 mg/level) and followed from 2 weeks to 1 year to
determine the ability of the nucleus and annulus to recover.  Proteoglycan
synthesis will be used as a measure of matrix formation and studied using
35S-sulfate with in vitro labeling and the biochemical characterization
including the chondrointin sulfate chain lengths, % chondrointin and
keratan sulfate.  This will be done using enzymes and analysis of the
glucosamine/galactosamine ratio by high pressure liquid chromatography.
Histologically, the samples will be followed at the light level after
Safranin-O fast green staining and by immunofluorescent techniques with
antibodies to matrix molecules such as fibronectin:  The samples will be
analyzed for changes in structure by morphometric analysis.  The changes in
the adjacent facet joints will also be followed for possible degenerative
changes.  This will be done with a biochemical analysis of the cartilage
for water changes and changes in 35S-sulfate uptake and matrix protein
alterations.  The histology of the cartilage and bone will be followed by
prelabeling in the animals with tetracycline analogs and using both light &
fluorescent microscopy.  In addition to remodeling after chymopapain
injection, the proteases elaborated by the nucleus during early remodeling
will be followed using specific substrates and inhibibors.

## Key facts

- **NIH application ID:** 3156196
- **Project number:** 5R01AR032145-06
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **SAM.gov UEI:** KABJZBBJ4B54
- **Principal Investigator:** DAVID S BRADFORD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $119,537
- **Award type:** 5
- **Project period:** 1983-04-01 → 1990-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156196

## Citation

> US National Institutes of Health, RePORTER application 3156196, RECOVERY OF INTERVERTEBRAL DISC AFTER ENZYME TREATMENT (5R01AR032145-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156196. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*