Original animal model of lumbar disc degeneration

ABSTRACT

Purpose: Disc degeneration (DD) is a common cause of low back pain, which represents one of the most widespread public health problems in the world. Therefore, the establishment of a reproducible animal model is indispensable to understand the pathogenic mechanisms of DD and to test new therapeutic strategies. From this perspective, the fundamental objective of this study was to elucidate the effect of ovariectomy in establishing a new animal model of DD in rats.

Methods: 36 female Sprague-Dawley rats were divided into four groups of 9 rats: Group 1: Negative control (Sham): Only an abdominal skin incision and sutures were performed. Group 2: Ovariectomy (OVX): Removal of two ovaries through a transverse incision in the middle of the abdomen. Group 3: Puncture (Punct): Puncture of lumbar intervertebral discs (L3/4, L4/5, and L5/6) by a 21 G needle. Group 4: Puncture+ovariectomy (Punct+OVX): Removal of two ovaries and puncture of L3/4, L4/5, and L5/6 discs. The rats were euthanized 1, 3, and 6 weeks post-surgery, and the discs were harvested. Validity was assessed by radiography, histology, and biochemistry (water content).

Results: Disc height, water content, and histologic score decreased significantly in the last 3 groups and at all three-time points (P < 0.05). DD progressed over time in the Punct and Punct+OVX groups (P < 0.05). The changes were more severe in the Punct+OVX group compared to the Punct group and the OVX group.

Conclusion: The combination of puncture and ovariectomy induced rapid and progressive DD in the lumbar discs of rats without spontaneous recovery.

KEYWORDS:

• Disc degeneration
• intervertebral disc
• puncture
• ovariectomy
• animal model

Disclosure statement

Each author certifies that he or she, or a member of his or her immediate family, has no commercial association (i.e. consultancies, stock ownership, equity interest, patent/licensing arrangement, etc.) that might pose a conflict of interest in connection with the submitted manuscript.

Data availability statement

The data used in this study are available on request from the first author ([email protected]).

Ethics approval

Experiments were carried out in conformity with the Tunisian ethical committee for the Care and Use of Laboratory Animals, adhering to the internationally recognized principles and judged recommendable by the Committee of Animal Ethics (approval no. 94–1939).

Additional information

Funding

There was no external funding in the preparation of this manuscript.