Exploring TRPV4-Related Mechanisms in Acupotomy Treatment of Discogenic Low Back Pain: An Exploratory Pilot Study in a Rat Model

Objective To explore preliminary associations between acupotomy and transient receptor potential vanilloid 4 (TRPV4)–related calcium accumulation and inflammatory responses in a rat model of discogenic low back pain (DLBP). Methods A DLBP model was established in male Sprague Dawley rats by L4/5 disc puncture. Twelve rats were randomized into control, sham-operated, model, and acupotomy groups ( n = 3 each). The acupotomy group received standardized paraspinal acupotomy once daily for 14 days; other groups received sham procedures or no treatment. Thermal withdrawal latency, descriptive gait observation, and body weight were assessed. HE staining was used for histopathology. Ca 2+ concentrations in muscle and disc tissues, serum TNF-α, IL-1β, and IL-18 levels, and TRPV4 protein and mRNA expression were measured. Results Thermal withdrawal latency supported successful model establishment but did not provide conclusive evidence of behavioral analgesia between the model and acupotomy groups. Descriptive gait observation and body weight monitoring showed directional functional and postoperative recovery trends after acupotomy. Histological examination revealed qualitative morphological features suggestive of partial improvement of disc structure and visually lower inflammatory cell presence. Acupotomy was accompanied by directionally lower Ca 2+ accumulation and lower serum inflammatory cytokine levels. In parallel, TRPV4 protein and mRNA expression were partially attenuated relative to the model group but remained elevated compared with controls. Conclusion Acupotomy was associated with partial attenuation of calcium accumulation, systemic inflammation, and TRPV4 expression in this exploratory DLBP model. Because behavioral evidence was limited and no TRPV4-specific intervention was performed, these findings should be interpreted as preliminary, associative, and hypothesis-generating.