Effects of Chronic Treatment With Two Selective 5-HT2 Antagonists on Sleep in theRat

摘要

The effect of chronic administration of ICI 169,369 and ICI 170,809, twoselective 5-HT2 antagonists, on sleep was studied in rats. As previously shown, the acute effect of ICI 170,809 was to increase latency to rapid eye movement sleep (REMS), decrease the number of REM periods (REMPs), suppress the cumulative amount of REMS over 12 hr and increase the duration of REMPs in the first 6 hr, while having no effect on non-REM sleep (NREMS). Administration of ICI 169,369 had similar effects except that no change was seen in the duration of REMPs and cumulative REMS was suppressed for 24 hr. When given 2X daily for 5 days, tolerance to the REMS suppressant effects developed in both drugs. After discontinuation of treatment, a REMS rebound occurred after ICI 170,809, but not ICI 169,369. No significant effect on NREMS was seen after administration of ICI 170,809, whereas ICI 169,369 lowered 24 hr cumulative NREMS on the fifth day of administration. Serotonin 2 antagonists, ICI 170,809, ICI 169,369, Sleep, REM, Rats.