| Abstract: | Animal models of intervertebral disc degeneration play an important role inclarifying the physiopathological mechanisms and testing novel therapeuticstrategies. The objective of the present study is to describe a simple animalmodel of disc degeneration involving Wistar rats to be used for researchstudies. Disc degeneration was confirmed and classified by radiography, magneticresonance and histological evaluation. Adult male Wistar rats were anesthetizedand submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7and 8-9 of the coccygeal vertebrae. The needle was inserted into the discsguided by fluoroscopy and its tip was positioned crossing the nucleus pulposusup to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s.To grade the severity of intervertebral disc degeneration, we measured theintervertebral disc height from radiographic images 7 and 30 days after theinjury, and the signal intensity T2-weighted magnetic resonance imaging.Histological analysis was performed with hematoxylin-eosin and collagen fiberorientation using picrosirius red staining and polarized light microscopy.Imaging and histological score analyses revealed significant disc degenerationboth 7 and 30 days after the lesion, without deaths or systemic complications.Interobserver histological evaluation showed significant agreement. There was asignificant positive correlation between histological score and intervertebraldisc height 7 and 30 days after the lesion. We conclude that the tail discpuncture method using Wistar rats is a simple, cost-effective and reproduciblemodel for inducing disc degeneration. |
