Rapid eye movement (REM)-sleep during and after continuous infusion of the oxazoline derivate S3341: a comparison with clonidine.

The frequency and duration of rapid eye movement (REM)-sleep episodes were examined in normotensive rats during and after cessation of continuous infusion of either clonidine (10 micrograms/kg/h) or the oxazoline derivative S3341 (50 micrograms/kg/h) for 10 days. Both compounds abolished REM-sleep during the infusion. On cessation of the clonidine infusion there was a rebound increase in the frequency and duration of REM-sleep episodes. These episodes were associated with markedly exaggerated blood pressure fluctuations. On cessation of the S3341 infusion, the frequency and duration of REM-sleep episodes returned to control levels. Blood pressure responses were not different from controls. These post-infusion differences may be related to the greater degree of selectivity of S3341 for the alpha 2-adrenoceptor rather than the alpha 1-adrenoceptor subtype.