Vasotocin and sleep in prepubertal boys: its suppression by valproic acid

In order to investigate a possible involvement of the GABA-ergic neurotransmission in the effects of arginine vasotocin (AVT) hormone on human sleep, we administered in 20 healthy prepubertal boys (aged 7-12 years), by an intra-nasal route, AVT (1 microgram) alone or 10 minutes after an intra-nasal dose of valproic acid (VA) (1, 10 and 50 micrograms). Whether the dose of 50 micrograms VA alone produced a quasi-total insomnia for all recording time (3h), the doses of 1 and 10 micrograms VA were without any apparent effect on sleep parameters. However, whatever be the dose of VA, it produced a total suppression of the hypnogenic effects of AVT. The results suggest not only a possible involvement of the GABA-ergic mechanisms in mediating the hypnogenic properties of AVT in man, but also that VA could be used in the treatment of excessive sleep syndromes, especially of narcolepsy.