The circadian rhythm of LH release can be shifted by injections of a benzodiazepine in female golden hamsters.

Three daily injections of the short-acting benzodiazepine, triazolam, induced pronounced phase shifts in the onset of both the circadian surge in pituitary LH release and the circadian rhythm of locomotor activity in ovariectomized hamsters treated with estrogen. Both the magnitude and the direction of the phase shifts in these two rhythms were similar. These results indicate that a master circadian clock underlying diverse behavioral and endocrine rhythms can be reset by treatment with triazolam.