Propofol and Ketamine-induced Anesthetic Depth-dependent Decrease of CaMKII Phosphorylation Levels in Rat Hippocampus and Cortex

Abstract

Ca/calmodulin-dependent protein kinase II (CaMKII) activation through autophosphorylation at threonine 286 was involved in the modulation of neuronal excitability and neurotransmission. Both propofol and ketamine may affect the intracellular Ca levels through N-methyl-D-aspartate receptors or voltage-dependent Ca channels, but they have different mechanisms in general anesthesia. The purpose of this study was to investigate the effects of propofol and ketamine on CaMKII total protein and phosphorylation (p-CaMKII) levels in the brain of rats. We found that both propofol and ketamine could induce a decrease of p-CaMKII, not CaMKII total protein, in an anesthetic depth-dependent manner, whereas only ketamine caused a dose (50, 100, and 150 mg/kg)-dependent depression of p-CaMKII in hippocampus and frontal cortex of rats after intraperitoneal injections for 30 minutes. The significant depressions of p-CaMKII started at 5 minutes both in hippocampus and frontal cortex of rats after 100 mg/kg propofol treatment, whereas 100 mg/kg ketamine-induced significant depression of p-CaMKII initiated at 30 minutes in hippocampus and 5 minutes (no reduction observed at 15 min) in frontal cortex of rats. The maximum reduction of p-CaMKII with both drugs was at 60 minutes, and then restored to control level at 240 minutes. In addition, we confirmed the depression of p-CaMKII in hippocampus and frontal cortex of rats after 100 mg/kg of propofol or ketamine treatment for 60 minutes by using immunostaining. These results suggested that decreased p-CaMKII levels correlate with anesthetic depths achieved by propofol and ketamine, which may be related to the effects of propofol and ketamine on central nervous system function and their clinical effect.

Inhibition of Neuron-Specific CREB Dephosphorylation is Involved in Propofol and Ketamine-Induced Neuroprotection Against Cerebral Ischemic Injuries of Mice

“…Similar to our previous studies [31,32], the frozen samples were rapidly thawed, homogenized at 4°C in Buffer C [5 mM Tris-Cl, pH 7.5, containing 2 mM DTT, 2 mM EDTA, 1 mM EGTA, 5 lg/ml each of leupeptin, aprotinin, pepstatin A and chymostatin, 50 mM potassium fluoride, 50 lM okadaic acid, 5 mM sodium pyrophosphate and 2% sodium dodecyl sulfate (SDS)] and sonicated to dissolve the tissue completely. Protein concentration was measured with the Bradford assay kit by using albumin diluted in lysis buffer as standard.…”

Isoflurane preconditioning and postconditioning in rat hippocampal neurons

“…Our results also suggest that AIP and KN93 may share mechanisms with isoflurane preconditioning and postconditioning for neuroprotection, indicating that inhibition of CaMKII may play a role in isoflurane preconditioning- and postconditioning-induced neuroprotection. The intravenous anesthetics propofol and ketamine have been shown to inhibit CaMKII phosphorylation/activation (Cui et al, 2009). It is not known yet whether volatile anesthetics, including isoflurane, also reduce CaMKII activation.…”

“…Interestingly, CaMKII levels in neurons have been shown to decrease during ischemia, and this decrease is attenuated by isoflurane preconditioning (Blanck et al, 2000). Also, anesthetics have been shown to affect CaMKII activity as measured by phosphorylation of CaMKII (Cui et al, 2009). In addition, the isoflurane preconditioning effect on neurons was abolished by calmidazolium, a compound that inhibits calcium-bound calmodulin (Bickler et al, 2005).…”

CaMKII Phosphorylation in Primary Somatosensory Cortical Neurons is Involved in the Inhibition of Remifentanil-induced Hyperalgesia by Lidocaine in Male Sprague-Dawley Rats

“…[14][15][16] Specifically, after freezing in liquid nitrogen, the tissues were supplemented with cold lysis buffer (7 mL/mg) at 41C. The lysis buffer contained the following ingredients: 50 mM Tris-Cl, pH 7.5; 2 mM dithiothreitol (DTT); 2 mM EDTA; 1 mM EGTA; 50 mM 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride; 5 mg/mL leupeptin; 5 mg/mL aprotinin; 5 mg/mL pepstatin A; 5 mg/mL chymostatin; 50 mM KF (potassium fluoride); 50 mM Okadaic acid; 5 mM sodium pyrophosphate; and 2% sodium dodecyl sulfate (SDS).…”