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Updated: May 29, 2026
Murine Hind Limb Explant Model for Studying the Mechanobiology of Achilles Tendon Impingement
Published on: December 8, 2023
Increased expression of cannabinoid CB₁ receptors in Achilles tendinosis
Emmelie Björklund1, Sture Forsgren, Håkan Alfredson
1Pharmacology Unit, Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden. emmelie.bjorklund@pharm.umu.se
Background:
The endogenous cannabinoid system is involved in the control of pain. However, little is known as to the integrity of the cannabinoid system in human pain syndromes. Here we investigate the expression of the cannabinoid receptor 1 (CB₁) in human Achilles tendons from healthy volunteers and from patients with Achilles tendinosis.
Methodology:
Cannabinoid CB₁ receptor immunoreactivity (CB₁IR) was evaluated in formalin-fixed biopsies from individuals suffering from painful Achilles tendinosis in comparison with healthy human Achilles tendons.
Principal Findings:
CB₁IR was seen as a granular pattern in the tenocytes. CB₁IR was also observed in the blood vessel wall and in the perineurium of the nerve. Quantification of the immunoreactivity in tenocytes showed an increase of CB₁ receptor expression in tendinosis tissue compared to control tissue.
Conclusion:
Expression of cannabinoid receptor 1 is increased in human Achilles tendinosis suggesting that the cannabinoid system may be dysregulated in this disorder.
