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

Abstract

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(ISO), in rats treated for 21 days with WIN 55,212-2 MAC(ISO + WIN55), and in rats 8 days after stopping treatment with WIN 55,212-2 (MACISO + WIN55 + 8D). Results: The MAC(ISO) was 1.32 0.06. In the MAC(ISO + WIN55) group, the MAC increased to 1.69 0.09 (28%, p-value (0.0001). Eight days after stopping treatment with WIN55, the MAC did not decrease significantly, 1.67 0.07 (26%, p-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.