Objective Dexmedetomidine is a highly selective alpha-2 adrenergic receptor agonist with sedative and analgesic properties but without respiratory depression effect and has been widely used in perioperative anesthesia. Here we performed a systematic review and meta-analysis to evaluate the effect of dexmedetomidine on maintaining perioperative hemodynamic stability in elderly patients.Methods PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched for randomized-controlled trials (RCTs) on the application of dexmedetomidine in maintaining perioperative hemodynamic stability in elderly patients from their inception to September, 2021. The standardized mean differences (SMD) with 95% confidence interval (CI) were employed to analyze the data. The random-effect model was used for the potential clinical inconsistency.Results A total of 12 RCTs with 833 elderly patients (dexmedetomidine group, 546 patients; control group, 287 patients) were included. There was no significant increase in perioperative heart rate (HR), mean arterial pressure (MAP), and diastolic blood pressure (DBP) in the dexmedetomidine group before and during the operation. In addition, the variations of hemodynamic indexes including HR, MAP, SBP (systolic blood pressure), and DBP were significantly lower in the dexmedetomidine group compared with the control group (HR: SMD = -0.87, 95% CI: -1.13 to -0.62; MAP: SMD = -1.12, 95% CI: -1.60 to -0.63; SBP: SMD = -1.27, 95% CI: -2.26 to -0.27; DBP: SMD = -0.96, 95% CI: -1.33 to -0.59). Subgroup analysis found that with the prolongation of 1.0 μg/kg dexmedetomidine infusion, the patient's heart rate declined in a time-dependent way.Conclusion Dexmedetomidine provides more stable hemodynamics during perioperative period in elderly patients. However, further well-conducted trials are required to assess the effective and safer doses of dexmedetomidine in elderly patients.
Humans ; Aged ; Dexmedetomidine/adverse effects* ; Hemodynamics ; Hypnotics and Sedatives/pharmacology* ; Blood Pressure ; Heart Rate

The purpose of this study was to investigate the effects of α₂ adrenergic receptor agonist dexmedetomidine on withdrawal symptoms in alcohol-dependent rats and the underlying mechanism, so as to provide a scientific basis for the treatment of alcohol withdrawal syndrome (AWS). Adult Sprague-Dawley (SD) male rats were orally administered with 6% aqueous alcohol continuously for 28 d to establish alcohol drinking model, and then stopped drinking to induce AWS. Enzyme-linked immunosorbent assay (ELISA) was used to determine the content of norepinephrine (NE) in the locus coeruleus and hippocampus of rats. Dexmedetomidine (5, 10, and 20 μg/kg) was intraperitoneally injected respectively when the rats showed significant AWS. In some rats, α₂ adrenergic receptor antagonist yohimbine was injected into hippocampus in advance. The results showed that, compared with the control group, the 6 h withdrawal group exhibited significantly increased AWS score and amount of repeat drinking. The NE contents in hippocampus and locus coeruleus of the last drinking and the 6 h withdrawal groups were significantly increased compared with those of the control group. Dexmedetomidine intervention significantly decreased AWS score and hippocampus NE content in the 6 h withdrawal group, while yohimbine could reverse these effects of dexmedetomidine. These results suggest that dexmedetomidine might improve the withdrawal symptoms in alcohol-dependent rats via activating α₂ adrenergic receptor.
Adrenergic alpha-2 Receptor Agonists/therapeutic use* ; Alcoholism/drug therapy* ; Animals ; Dexmedetomidine/therapeutic use* ; Hippocampus/metabolism* ; Male ; Norepinephrine ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, alpha-2/metabolism* ; Substance Withdrawal Syndrome/drug therapy* ; Yohimbine/pharmacology*

OBJECTIVE: Dexmedetomidine (DEX), the most specific α ₂-adrenergic receptor agonist widely used for its sedative and analgesic properties, has been reported to upregulate HIF-1α expression to protect hypoxic and ischemic tissues. However, it is largely unclear whether DEX can also upregulate Hypoxia-inducible factor-1 alpha (HIF-1α) expression and its downstream vascular endothelial growth factor-A (VEGFA) in cancer tissues with oxygen-deficient tumor microenvironment. METHODS: We used SMMC-7721 cells, MHCC97-H cells, and a mouse model of orthotopic hepatic carcinoma to explore the effect of DEX on angiogenesis and vasculogenic mimicry (VM) and its mechanism. Under normoxic (20% O ₂) and hypoxic (1% O ₂) conditions, DEX was used to intervene cells, and yohimbine was used to rescue them. RESULTS: The results showed that DEX promoted angiogenesis and VM in human liver cancer cells within a certain dose range, and the addition of yohimbine inhibited this effect. DEX could activate HIF-1α/VEGFA pathway, which was further verified by silencing HIF-1α. Consistently, in vivo results also showed that DEX can up-regulate HIF-1α/VEGFA expression, and enhance the number of VM channels and microvessel density (MVD). CONCLUSION We believe that HIF-1α/VEGFA might be an important signaling pathway by which DEX promotes angiogenesis and VM formation in human hepatocellular carcinoma, whereas α ₂-adrenergic receptor mediation might be the critical mechanisms.
Animals ; Humans ; Mice ; Adrenergic alpha-2 Receptor Agonists/pharmacology* ; Carcinoma, Hepatocellular ; Cardiovascular Physiological Phenomena ; Dexmedetomidine/pharmacology* ; Hypoxia ; Liver Neoplasms/drug therapy* ; Oxygen ; Tumor Microenvironment ; Vascular Endothelial Growth Factor A/genetics* ; Receptors, Adrenergic, alpha-2/metabolism*

The aim of the present study was to investigate the effects of dexmedetomidine (DEX) on acute liver injury induced by lipopolysaccharide (LPS)/D-galactosamine (D-Gal) and the underlying mechanism. Male BALB/c mice were intraperitoneally injected with LPS/D-Gal to induce acute liver injury model, and pretreated with DEX or in combination with the autophagy inhibitor, 3-methyladenine (3-MA) 30 min before injection. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, as well as myeloperoxidase (MPO) activity in liver tissue were determined with the corresponding kits. Serum tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) levels were determined by ELISA. The protein expression levels of LC3-II and P62 in liver tissue were determined by Western blot. Liver histopathological changes were detected by HE staining. The results showed that, compared with control group, LPS/D-Gal enhanced ALT and AST activity, increased TNF-α and IL-6 levels, as well as MPO activity, up-regulated LC3-II and P62 protein expression levels, and significantly induced pathological damage in liver tissue. DEX reversed the above changes in the LPS/D-Gal group, whereas these protective effects of DEX were blocked by 3-MA. The above results suggest that DEX alleviates LPS/D-Gal-induced acute liver injury, which may be associated with the up-regulation of LC3-II protein expression and the activation of autophagy.
Alanine Transaminase ; Animals ; Chemical and Drug Induced Liver Injury/drug therapy* ; Dexmedetomidine/pharmacology* ; Galactosamine/toxicity* ; Interleukin-6/blood* ; Lipopolysaccharides/toxicity* ; Liver ; Male ; Mice ; Mice, Inbred BALB C ; Microtubule-Associated Proteins/metabolism* ; Tumor Necrosis Factor-alpha/blood* ; Up-Regulation

The aim of this study was to investigate the effects of dexmedetomidine (Dex) on hepatic ischemia/reperfusion injury (HIRI) and the underlying mechanism. The in vitro HIRI was induced by culturing HL-7702 cells, a human hepatocyte cell line, under 24 h of hypoxia and 12 h of reoxygenation. Quantitative real time PCR (qRT-PCR) and Western blot were performed to detect the expression levels of long non-coding RNA MALAT1, microRNA-126-5p (miR-126-5p) and high mobility group box-1 (HMGB1). Bioinformatics prediction and double luciferase assay were used to verify the targeting relationship between miR-126-5p and MALAT1, HMGB1. Reactive oxygen species (ROS), malondialdehyde (MDA) and ATP levels in culture medium were detected by corresponding kits. The results showed that Dex significantly reduced the levels of ROS and MDA, but increased the level of ATP in HL-7702 cells with HIRI. HIRI up-regulated the expression levels of MALAT1 and HMGB1, and down-regulated the level of miR-126-5p. Dex reversed these effects of HIRI. Furthermore, Dex inhibited HIRI-induced cellular apoptosis, whereas MALAT1 reversed the effect of Dex. This inhibitory effect of Dex could be restored by up-regulation of miR-126-5p. The results suggest that Dex protects hepatocytes from HIRI via regulating MALAT1/miR-126-5p/HMGB1 axis.
Dexmedetomidine/pharmacology* ; HMGB1 Protein/genetics* ; Humans ; MicroRNAs/genetics* ; RNA, Long Noncoding/genetics* ; Reperfusion Injury/genetics*

Objective To explore the effect of dexmedetomidine(Dex)on sevoflurane-induced cognitive impairment in neonatal rats through Wnt signaling pathway. Methods Sixty 7-day-old SD rats were assigned into five groups:control group(without any intervention),Dex group(intraperitoneal injection of 25 μg/kg Dex),sevoflurane group(3% sevoflurane treatment for 4 hours),sevoflurane+Dex group(inhalation of 3% sevoflurane after injection of 25 μg/kg Dex for 4 hours),and sevoflurane+Dex+Wnt inhibitor group(Wnt inhibitor XAV393 and 25 μg/kg Dex were injected and 3% sevoflurane was inhaled for 4 hours).Three weeks later,Morris water maze was used to detect the cognitive function;TdT-mediated dUTP nick end labeling(TUNEL)staining was performed to detect the apoptosis of hippocampal neurons;neuronal nuclei (NeuN) staining was conducted to detect the survival of hippocampal neurons;Western blot was carried out to detect the expression of apoptosis-related proteins.The expression of the factors involved in Wnt/GSK-3β/β-catenin signaling pathway was detected by fluorescence quantitative polymerase chain reaction,and Western blot. Results Compared with the control group,there was no significant difference in the escape latency of Dex group(t=0.304,P=0.768);the escape latency in sevoflurane group(t=5.823,P=0.002),sevoflurane+Dex group(t=3.188,P=0.010),and sevoflurane+Dex+Wnt inhibitor group(t=5.784,P=0.002)was significantly prolonged.Compared with that in the sevoflurane group,the escape latency in sevoflurane+Dex group(t=3.646,P=0.005)was significantly shortened.Compared with that in sevoflurane+Dex group,the escape latency in sevoflurane+Dex+Wnt inhibitor group(t=3.296,P=0.008)was prolonged.Compared with that in the control group,the times of crossing platform in sevoflurane group(t=5.179, P=0.004),sevoflurane+Dex group(t=2.309,P=0.043),and sevoflurane+Dex+Wnt inhibitor group(t=3.871, P=0.003)decreased.Compared with that in sevoflurane group,the times of crossing platform in sevoflurane+Dex group(t=3.296,P=0.008)significantly increased.Compared with that in sevoflurane+Dex group,the times of crossing platform in sevoflurane+Dex+Wnt inhibitor group(t=2.361, P=0.041)reduced.Compared with the control group,there was no significant difference in the number of apoptotic cells in Dex group(t=1.920,P=0.127),and the number of apoptotic cells in sevoflurane group,sevoflurane+Dex group,and sevoflurane+Dex+Wnt inhibitor group increased by 16%(t=13.436,P=0.002),5%(t=7.752, P=0.001),and 11.5%(t=12.612,P=0.002),respectively.Compared with that in the sevoflurane group,the number of apoptotic cells in sevoflurane+Dex group and sevoflurane+Dex+Wnt inhibitor group decreased by 11%(t=8.521,P=0.002)and 5.5%(t=3.123,P=0.036),respectively.Compared with that in the sevoflurane+Dex group,the number of apoptotic cells in sevoflurane+Dex+Wnt inhibitor group increased by 6.5%(t=6.250,P=0.003).Compared with that in the control group,the number of positive cells in 0.15 mm
Animals ; Animals, Newborn ; Cognitive Dysfunction/chemically induced* ; Dexmedetomidine/pharmacology* ; Glycogen Synthase Kinase 3 beta ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/toxicity* ; Wnt Signaling Pathway ; beta Catenin/metabolism*

OBJECTIVE: To investigate the effect of dexmedetomidine combined with pulmonary protective ventilation against lung injury in patients undergoing surgeries for esophageal cancer with one-lung ventilation (OLV). METHODS: Forty patients with undergoing surgery for esophageal cancer with OLV were randomly divided into pulmonary protective ventilation strategy group (F group) and dexmedetomidine combined with protective ventilation strategy group (DF group; =20). In F group, lung protective ventilation strategy during anesthesia was adopte, and in DF group, the patients received intravenous infusion of dexmedetomidine hydrochloride (0.3 μg · kg ·h) during the surgery starting at 10 min before anesthesia induction in addition to protective ventilation strategy. Brachial artery blood was sampled before ventilation (T), at 30 and 90 min after the start of OLV (T and T, respectively) and at the end of the surgery (T) for analysis of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), arterial oxygenation pressure (PaO), oxygenation index (OI) and lung compliance (CL). RESULTS: At the time points of T, T and T, SOD level was significantly higher and IL-6 level was significantly lower in the DF group than in F group ( < 0.05). The patients in DF group showed significantly higher PaO, OI and CL index than those in F group at all the 3 time points. CONCLUSIONS Dexmedetomidine combined with pulmonary protective ventilation strategy can reduce perioperative lung injury in patients undergoing surgery for esophageal cancer with OLV by suppressing inflammation and oxidative stress to improve lung function and reduce adverse effects of the surgery.
Analgesics, Non-Narcotic ; pharmacology ; therapeutic use ; Dexmedetomidine ; pharmacology ; therapeutic use ; Esophageal Neoplasms ; drug therapy ; surgery ; Humans ; Lung ; drug effects ; surgery ; One-Lung Ventilation ; Oxidative Stress ; drug effects ; Treatment Outcome

Objective: To explore the protective effects of dexmedetomidine (Dex) against high glucose-induced epithelial-mesenchymal transition in HK-2 cells and relevant mechanisms. Methods: HK-2 cells were exposed to either glucose or glucose+Dex for 6 h. The production of ROS, morphology of HK-2 cells, and cell cycle were detected. Moreover, the expression of AKT, p-AKT, ERK, p-ERK, PI3K, E-Cadherin, Claudin-1, and α-SMA were determined and compared between HK-2 cells exposed to glucose and those exposed to both glucose and Dex with or without PI3K/AKT pathway inhibitor LY294002 and ERK pathway inhibitor U0126. Results: Compared with HK-2 cells exposed to high level of glucose, the HK-2 cells exposed to both high level of glucose and Dex showed: (1) lower level of ROS production; (2) cell morphology was complete; (3) more cells in G1 phase; (4) lower expression of p-AKT, p-ERK and α-SMA, higher expression of E-Cadherin and Claudin-1. PI3K/AKT inhibitor LY294002 and ERK inhibitor U0126 decreased the expression of p-AKT, p-ERK and α-SMA, and increased the expression of E-Cadherin and Claudin-1. Conclusion Dex can attenuate high glucose-induced HK-2 epithelial-mesenchymal transition by inhibiting AKT and ERK.
Adrenergic alpha-2 Receptor Agonists ; pharmacology ; Cell Line ; Dexmedetomidine ; pharmacology ; Epithelial-Mesenchymal Transition ; drug effects ; Glucose ; metabolism ; Humans ; MAP Kinase Signaling System ; drug effects ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; Signal Transduction ; drug effects

PURPOSE: To investigate whether dexmedetomidine (Dex) can reduce the production of inflammatory factor IL-1β by inhibiting the activation of NLRP3 inflammasome in hippocampal microglia, thereby alleviating the inflammatory response of the central nervous system induced by surgical injury. METHODS: Exploratory laparotomy was used in experimental models in this study. Totally 48 Sprague Dawley male rats were randomly divided into 4 groups (n = 12 for each), respectively sham control (group A), laparotomy only (group B); and Dex treatment with different doses of 5 μg/kg (group D1) or 10 μg/kg (group D2). Rats in groups D1 and D2 were intraperitoneally injected with corresponding doses of Dex every 6 h. The rats were sacrificed 12 h after operation; the hippocampus tissues were isolated, and frozen sections were made. The microglia activation was estimated by immunohistochemistry. The protein expression of NLRP3, caspase-1, ASC and IL-1β were detected by immunoblotting. All data were presented as mean ± standard deviation, and independent sample t test was used to analyze the statistical difference between groups. RESULTS: The activated microglia in the hippocampus of the rats significantly increased after laparotomy (group B vs. sham control, p < 0.01). After Dex treatment, the number was decreased in a dose-dependent way (group D1 vs. D2, p < 0.05), however the activated microglia in both groups were still higher than that of sham controls (both p < 0.05). Further Western blot analysis showed that the protein expression levels of NLRP3, caspase-1, ASC and downstream cytokine IL-1β in the hippocampus from the laparotomy group were significantly higher than those of the sham control group (all p < 0.01). The elevated expression of these proteins was relieved after Dex treatment, also in a dose-dependent way (D2 vs. D1 group, p < 0.05). CONCLUSION Dex can inhibit the activation of microglia and NLRP3 inflammasome in the hippocampus of rats after operation, and the synthesis and secretion of IL-1β are also reduced in a dose-dependent manner by using Dex. Hence, Dex can alleviate inflammation activation on the central nervous system induced by surgical injury.
Animals ; Dexmedetomidine ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Hippocampus ; metabolism ; Immunohistochemistry ; Inflammasomes ; metabolism ; Inflammation Mediators ; metabolism ; Injections, Intraperitoneal ; Interleukin-1beta ; metabolism ; Laparotomy ; adverse effects ; Male ; Microglia ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; metabolism ; Rats, Sprague-Dawley ; Time Factors

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a serious complication after surgery, especially in elderly patients. The anesthesia technique is a potentially modifiable risk factor for POCD. This study assessed the effects of dexmedetomidine, propofol or midazolam sedation on POCD in elderly patients who underwent hip or knee replacement under spinal anesthesia. METHODS: The present study was a prospective randomized controlled preliminary trial. From July 2013 and December 2014, a total of 164 patients aged 65 years or older who underwent hip or knee arthroplasty at China-Japan Friendship Hospital and 41 non-surgical controls were included in this study. Patients were randomized in a 1:1:1 ratio to 3 sedative groups. All the patients received combined spinal-epidural anesthesia (CSEA) with midazolam, dexmedetomidine or propofol sedation. The sedative dose was adjusted to achieve light sedation (bispectral index[BIS] score between 70 and 85). All study participants and controls completed a battery of 5 neuropsychological tests before and 7 days after surgery. One year postoperatively, the patients and controls were interviewed over the telephone using the Montreal cognitive assessment 5-minute protocol. RESULTS: In all, 60 of 164 patients (36.6%) were diagnosed with POCD 7 days postoperatively, POCD incidence in propofol group was significantly lower than that in dexmedetomidine and midazolam groups (18.2% vs. 40.0%, 51.9%, χ = 6.342 and 13.603, P = 0.012 and < 0.001). When the patients were re-tested 1 year postoperatively, the incidence of POCD was not significantly different among the 3 groups (14.0%, 10.6% vs. 14.9%, χ = 0.016 and 0.382, P = 0.899 and 0.536). CONCLUSION Among dexmedetomidine, propofol and midazolam sedation in elderly patients, propofol sedation shows a significant advantage in term of short-term POCD incidence.
Aged ; Cognitive Dysfunction ; epidemiology ; Dexmedetomidine ; pharmacology ; Female ; Humans ; Hypnotics and Sedatives ; pharmacology ; Male ; Midazolam ; pharmacology ; Middle Aged ; Neuropsychological Tests ; Postoperative Complications ; epidemiology ; Propofol ; pharmacology ; Prospective Studies