Human Intestinal Strips Showed Cannabinoid Tolerance Outside the Living Body
Human-origin tissue can provide human biological evidence without being a clinical trial. An intestinal-strip experiment induced tolerance to a synthetic cannabinoid after prolonged laboratory incubation.
The preparation measured contractions
Researchers compared human small-intestinal and guinea-pig myenteric-plexus preparations. Electrically evoked muscle contractions were assessed before and after incubation with WIN55,212-2 or comparison conditions.
The agonist response was lost after exposure
The abstract reports loss of the acute cannabinoid response after prolonged incubation with the active agonist. A tested kappa-opioid agonist retained similar potency in control and cannabinoid-tolerant human tissue, supporting selectivity rather than loss of every inhibitory response.
The antagonist result also depended on treatment
Rimonabant's effects on electrically stimulated contractions differed between control and tolerant preparations and between species. That variation cautions against treating an antagonist response as independent of exposure history or tissue context.
These are ex vivo functional measurements, not observations of a patient's bowel symptoms, analgesia or cannabis impairment. Tissue concentrations cannot simply be converted to a consumed dose. The study supports the existence of local cannabinoid adaptation in the tested human tissue while leaving absorption, metabolism, nervous-system effects and clinical outcomes outside its direct scope.
Related: interpreting cannabis tolerance claims.
Research cited
Guagnini F; Cogliati P; Mukenge S; Ferla G; Croci T. Tolerance to cannabinoid response on the myenteric plexus of guinea-pig ileum and human small intestinal strips. British journal of pharmacology (2006). doi:10.1038/sj.bjp.0706813. Findings discussed from the study abstract.
