Minimum Alveolar Concentration of Isoflurane in Rats Chronically Treated with the Synthetic Cannabinoid WIN 55,212-2.

Unlabelled: The minimum alveolar concentration MAC of isoflurane was measured in rats chronically treated with WIN 55,212-2.

Methods: The MAC of isoflurane was determined in 24 male rats from expiratory samples at time of tail clamping under the following conditions: without treatment MAC(), in rats treated for 21 days with WIN 55,212-2 MAC(), and in rats 8 days after stopping treatment with WIN 55,212-2 (MAC).

Results: The MAC() was 1.32 ± 0.06. In the MAC() group, the MAC increased to 1.69 ± 0.09 (28%, -value ≤ (0.0001). Eight days after stopping treatment with WIN55, the MAC did not decrease significantly, 1.67 ± 0.07 (26%, -value ≤ 0.0001).

Conclusions: The administration of WIN 55,212-2 for 21 days increases the MAC of isoflurane in rats. This effect does not disappear 8 days after discontinuation of treatment with the synthetic cannabinoid.