Effect of propofol on circadian variation of brain–derived neurotrophic factor
Abstract
Background & objective: Previous studies showed daily variations of brain–derived neurotropic factor (BDNF) but there is no evidence of any circadian rhythm of BDNF proteins and still there is no data regarding effect of propofol anesthesia on the circadian rhythmicity of BDNF protein in the brain. This study examined the effect of propofol anesthesia on circadian rhythm of BDNF protein in hippocampus and cortex.
Methodology: Male rats were treated with propofol anaesthesia (120 mg/kg) with their intralipid control. Subjects were sacrificed at four different zeitgeber times (ZT5, ZT11, ZT17 and ZT23). Here, ZT0 and ZT12 defining lights on and off respectively. The brains were removed and brain homogenates were prepared from hippocampus and cortex tissues. The amount of BDNF protein was assessed using ELISA (Millipore) on the brain supernatants.
Results: The main results showed that this circadian variation of BDNF protein in both the hippocampal and cortical structures is disturbed by the propofol anesthesia. Post–hoc analyses showed that animals treated with intralipid as control showed an effect on daily variation of BDNF in both hippocampal and cortical regions (all have P<0.01).
Conclusion: Our results provided the first evidence that BDNF protein expression follows a physiological circadian rhythm in hippocampus and cortex with a maximum activity evidenced at ZT5 (5h after light on) and for the first time, we evidenced that this circadian rhythm of BDNF protein is dysregulated by the propofol anaesthesia.
Key words: Circadian rhythms; Propofol; Cortex; Hippocampus; ELISA; BDNF
Abbreviations: BDNF – Brain–derived neurotrophic factor; RT–PCR – Reverse transcription polymerase chain reaction
Citation: Rafiq M. Effect of propofol on circadian variation of brain–derived neurotrophic factor. Anaesth. pain intensive care 2021;25(3):345–348. DOI: doi.org/10.35975/apic.v25i3.1528
Received: April 28, 2019; Reviewed: February 26, March 31, 2021; Accepted: March 31, 2021
