Factors Affecting Small Molecule Trans-Endplate Transport into the Intervertebral Disc In Vivo

Low back pain is a serious issue afflicting many in the United States population. While idiopathic in nature, low back pain is commonly associated with degenerative changes to the intervertebral disc (IVD). As the IVD is avascular, it obtains its nutrients and exchanges wastes via diffusion through the vertebral endplates. When the degenerative changes occur, the endplates become sclerotic, which diminishes diffusion and reduces nutrient transport into the disc. If the disc is prevented from receiving nutrients and expelling waste products, it will deteriorate, thus linking disc degeneration to reduction in disc transport. Therefore, to prevent disc degeneration and accompanying low back pain, it may be possible to develop pharmaceutical interventions to enhance trans-endplate transport into the disc by targeting and enhancing microvascularity in the endplate. In this study, the effects of nimodipine, a vasodilative and angiogenic drug, and the effects of nicotine, a vasoconstrictive drug, on endplate microvascularity are investigated. Data from this study indicate that nimodipine increased diffusion into the disc by 8.4% compared to the control and nicotine had early stage degenerative findings such as decreased proteoglycans and water.