Rolipram, an antidepressant that increases the availability of cAMP, transiently enhances wakefulness in rats

A study was carried out on the effects on sleep of rolipram, an antidepressant that increases the availability of cAMP by inhibiting a phosphodiesterase isoenzyme. Rats were treated with rolipram (0.1 or 1 mg/kg) twice a day (at light and dark onset) for 11 days, after a chronic period of injection of physiological saline for habituation purposes. The sleep-wake activity was recorded for 12 h following the injection at light onset on the baseline day (physiological saline), on rolipram days 1, 5, and 11, and also on day 12, when physiological saline was injected again (withdrawal day). The high (1 mg/kg) dose of rolipram enhanced wakefulness (W) in postinjection h 1 on day 1 of rolipram treatment. After administration of 0.1 mg/kg rolipram, only a tendency to an increase in W was noted. The promotion of W might be attributed, at least in part, to an increased release of noradrenaline due to a cAMP-mediated stimulation of tyrosine hydroxylase.