Day and Night Administration of Sevoflurane Effect of Melatonin Levels in Rats

Background: The aim of this study was to investigate the effects of sevoflurane anesthesia in day/night cycles on melatonin levels in rats. Methods: Fifteen-day-old 24 rats were included in the study and randomized into four groups according to anesthetic (sevoflurane or control) and the timing of administration (night phase or day phase). 2.6 % sevoflurane and 6 L.min-1 of oxygen were delivered to rats, between 07:00 pm-01:00 am (night group) and 07:00 am-01:00 pm (day group). After the sacrification of the rats, blood samples were taken and samples were centrifuged and plasma melatonin levels were measured by radioimmunoassay. Results: When Group night sevoflurane (GN-S) was compared with Group night control (GN-C), significant difference was found on melatonin levels (p=0,002). When plasma melatonin levels were compared between Group day sevoflurane (GD-S) and Group day control (GD-C), melatonin level of Group Day sevoflurane was found significantly higher (p=0.002). Similarly, when plasma melatonin levels were compared between GN-C and GD-C groups, melatonin level of GN-C was found significantly higher (p=0.002). Conclusions: In this study, it has been ascertained that 2.6% sevoflurane administered for six hours during the day and night periods increased melatonin levels significantly in 15 days old rats.