Circadian variation of methyleugenol anesthesia in albino rats

ABSTRACT

In Wistar rats synchronized to a 12-h light/12-h dark cycle (lights on from 0800 to 20h), the ip injection of methyleugenol (200 mg/Kg) at 0800, 1200 and 1600 h significantly increased the sleeping time (time between loss and recovery of righting reflex) when compared to animals anesthetized at 2000, 2400 and 0400h. These data provide another example of the importance of circadian rhythms in biological systems and their practical relevance to pharmacology