Status epilepticus (SE) is a medical emergency associated with a high rate of mortality if not treated promptly. Exogenous and endogenous
cannabinoids have been shown to possess
anticonvulsant properties both in vivo and in vitro. Here we study the influence of
endocannabinoid metabolism on the development of
kainic acid-induced SE in guinea pigs. For this purpose, the inhibitors of
endocannabinoid transport,
AM404, and enzymatic (
fatty acid amide hydrolase) degradation,
URB597, were applied.
Cannabinoid CB1 receptor antagonist,
AM251, was also tested. Animal behavior as well as local electric field potentials in four structures: medial septum, hippocampus, entorhinal cortex and amygdala were analyzed when
AM404 (120nmol),
URB597 (4.8nmol) or
AM251 (20nmol) were administrated alone or together with 0.4μg of
kainic acid. All substances were injected i.c.v.
AM404,
URB597 or
AM251 administered alone did not alter markedly local field potentials of all four studied structures in the long-term compared with their basal activity.
AM404 and
URB597 significantly alleviated
kainic acid-induced SE, decreasing behavioral manifestations, duration of seizure events and SE in general without changing the amplitude of local field potentials.
AM251 did not produce distinct effects on SE in terms of our experimental paradigm. There was no apparent change of the seizure initiation pattern when
kainic acid was coadministrated with
AM404,
URB597 or
AM251. The present study provides electrophysiologic and behavioral evidences that inhibition of
endocannabinoid metabolism plays a protective role against
kainic acid-induced SE and may be employed for therapeutic purposes. Further investigations of the influences of
cannabinoid-related compounds on SE genesis and especially epileptogenesis are required.