Blood Alcohol Differences in CB1-Deficient Mice Depended on the Exposure Regimen
A blood-alcohol difference at a high experimental exposure did not establish a general metabolic difference between CB1-deficient and control mice. A review also reports null blood-concentration comparisons at more moderate doses.
A high-exposure comparison was positive
Pava and Woodward describe increased plasma ethanol concentrations in CB1-deficient mice after a high-dose injected exposure and forced pulmonary alcoholization. The route, dose and sampled matrix belong with this observation.
Other exposure comparisons were null
The review notes that genotype differences in blood ethanol concentration were not observed at more moderate doses in the cited studies. It therefore characterizes effects on alcohol metabolism as modest rather than a universal explanation for altered behavior.
Concentration and behavioral response need separate analysis
Greater sedation or incoordination could reflect exposure, sensitivity or both. When concentrations do not differ under the relevant conditions, a result from a different high-dose protocol cannot establish a pharmacokinetic explanation. These animal findings concern genetic CB1 deletion, not a test of cannabis co-use in humans. They illustrate why metabolic claims should retain the dose, route, matrix and null comparisons that constrain them.
Related reading: Alcohol–Endocannabinoid Reviews Need to Keep Stages of Dependence Separate.
Research cited
Pava MJ, Woodward JJ. A Review of the Interactions between Alcohol and the Endocannabinoid System: Implications for Alcohol Dependence and Future Directions for Research (2012). The experiments discussed here are described through this supplied review.
