AM-1346 - a Synthetic Cannabinoid
AM1346 is a cannabinoid receptor type 1 (CB1R) anandamide analog [alkoxyacid amide of N-eicosa-(5Z, 8Z, 11Z, 14Z)-tetraenylamine] with high affinity and selectivity for the CB1 vs. CB2 receptor [Ki (CB1)=1.5 nmol/l; Ki (CB2)=152 nmol/l].
The present study characterized the effects of AM1346 (5.6–18 mg/kg) and its interaction with the CB1R antagonist/inverse agonist SR141716 (1–5.6 mg/kg) on open-field behaviours of rats. AM1346 reduced ambulation (horizontal activity), rearing (vertical activity) and increased the degree of circling and the latency to leave the central area of the open-field arena.
AM1346 also tended to reduce defecation and to increase vocalization in a dose-dependent manner. In pre-treatment studies, SR141716 completely blocked the effects of AM1346 on circling and latency and partially antagonized the effects of 18 mg/kg AM1346 on ambulation and rearing. SR141716 also tended to decrease AM1346-induced vocalization in a dose-dependent manner.
Earlier studies have shown that SR141716, given alone, can increase grooming behaviour and, as well, produces dose-related increases in scratching.
In the present studies, these effects were attenuated in a dose-related manner by AM1346. The present profile of behavioural effects for AM1346 is consistent with its designation as a CB1R agonist.
When combined with drug discrimination data (surmountable antagonism of effects of SR141716 by Δ9-THC and AM1346 but not by methanandamide, i.e. AM356), these data indicate that the anandamide analog AM1346 may be more behaviourally similar to cannabinoids like Δ9-THC than to other anandamide-based molecules such as methanandamide.