Discovery of N-(2-benzyl-4-oxochroman-7-yl)-2-(5-(ethylsulfonyl) pyridin-2-yl) acetamide (b12) as a potent, selective, and orally available novel retinoic acid receptor-related orphan receptor γt inverse agonist.

The nuclear receptor retinoic acid receptor-related orphan receptor γ (RORγ, NR1F3, or RORc) exists in two isoforms, with one isoform (RORγ or RORc1) widely expressed in a variety of tissues, and the expression of the second isoform (RORγt or RORc2) restricted to the thymus and cells of the immune system. RORγt is a key regulator of the development and functions of T-helper 17 (Th17) cells. Clinical proof-of-concept (PoC) with small molecule inverse agonists of RORγt has been achieved with VTP-43742 (Phase II) for the treatment of psoriasis, and pre-clinical PoC for this mechanism has also been established for the treatment of autoimmune diseases. A series of aryl sulfonyl derivatives as novel RORγt inverse agonists were designed and synthesized based on VTP-43742. We conducted structural modifications that improved the activity profile. In pharmacodynamic (PD) studies, oral administration of compound b12 showed robust and dose-dependent inhibition of IL-6 and IL-17A cytokine expression. The ability of compound b12 to reduce the levels of IL-6 and IL-17A in vivo after oral dosing in mice, and a corresponding reduction in skin inflammation further supports the potential of small molecule RORγt modulation as a therapeutic target for the treatment of inflammatory diseases.

Etomidate increases mortality in septic rats through inhibition of nuclear factor kappa-B rather than by causing adrenal insufficiency.

BACKGROUND: Both hyperinflammation during sepsis and etomidate can suppress adrenal function. In this study, we explored whether pretreatment with etomidate can relieve adrenal suppression and its impact on outcomes of cecal ligation and puncture (CLP)-induced septic rats. MATERIALS AND METHODS: Rats (n = 18 per group) were divided in seven groups, including two control groups and treated with different combinations of a small pretreatment dose (0.6 mg/kg) and a large continuous dose (2 mg/kg/h over 2 h) of etomidate to evaluate the impact of the different administration combinations on the adrenal glands and outcomes in the septic rats. Animals (n = 8 per group) were euthanized at 24 h after CLP and blood samples and adrenal glands were then collected for further measurements. The remaining rats (n = 10 per group) were used to observe the 7-d survival rate post-CLP. RESULTS: The survival rate (30%) was much lower in the group pretreated with a small dose before CLP surgery and followed by a large dose of etomidate than in the other groups. Etomidate decreased serum corticosterone, but not adrenocorticotropic hormone levels in septic rats, and also decreased serum tumor necrosis factor-alpha and interleukin-6 levels. In rat pretreated with a small dose of etomidate, the toll-like receptor-4 expression level in the adrenal glands was decreased and nuclear factor kappa-B (NF-kappa B) translocation was inhibited. CONCLUSIONS: The mortality of septic rats and degree of adrenal injury caused by etomidate are not correlated. The etomidate-induced inhibition of inflammation and NF-kappa B translocation, which was more significant than adrenal suppression, may be responsible for the increased mortality in septic rats.

[The changes of p-Akt/MuRF1/FoxO1 proteins expressions in the conditions of training and immobilization in rats' gastrocnemius muscle].

This study was aimed to investigate the changes of muscle protein synthesis and degradation under different movement conditions, so as to provide theoretical basis for muscle atrophy mechanism. Sprague Dawley (SD) rats were randomly divided into control, endurance training (treadmill training), hind limb overhanging and eccentric training (treadmill training, angle -16º) groups. The gastrocnemius muscles of rats were taken and weighed. The muscle was sectioned, and HE staining was employed to determine the cell's cross-sectional area. Protein expression of p-Akt was measured by immunohistochemistry; and the expressions of MuRF1 and FoxO1 were determined by Western blot. The results showed that, compared with control group, hind limb overhanging and eccentric training groups exhibited decreased muscle weight and cross-sectional area, but endurance training group did not show any changes. The expressions of p-Akt in endurance and eccentric training groups, not in hind limb overhanging group, were significantly higher than that in control group. Compared with that of control, MuRF1 protein remained unchanged in endurance training groups, but was increased in eccentric training and hind limb overhanging groups; FoxO1 protein was decreased in endurance training group, but was increased in eccentric training and hind limb overhanging groups. These results indicate that movement (endurance and eccentric training) can activate Akt expression, but does not increase muscle weight, whereas eccentric training and hind limb overhanging can increase the expressions of MuRF1 and FoxO1, and induce amyotrophy, suggesting MuRF1 and FoxO1 are major determinant factors in muscle atrophy.

A multi-constituent model for assessing the effect of impeller shroud on the thrombosis potential of a centrifugal blood pump.

Centrifugal blood pumps can be used for treating heart failure patients. However, pump thrombosis has remained one of the complications that trouble clinical treatment. This study analyzed the effect of impeller shroud on the thrombosis risk of the blood pump, and predicted areas prone to thrombosis. Multi-constituent transport equations were presented, considering mechanical activation and biochemical activation. It was found that activated platelets concentration can increase with shear stress and adenosine diphosphate(ADP) concentration increasing, and the highest risk of thrombosis inside the blood pump was under extracorporeal membrane oxygenation (ECMO) mode. Under the same condition, ADP concentration and thrombosis index of semi-shroud impeller can increase by 7.3% and 7.2% compared to the closed-shroud impeller. The main reason for the increase in thrombosis risk was owing to elevated scalar shear stress and more coagulation promoting factor-ADP released. The regions with higher thrombosis potential were in the center hole, top and bottom clearance. As a novelty, the findings revealed that impeller shroud can influence mechanical and biochemical activation factors. It is useful for identifying potential risk regions of thrombus formation based on relative comparisons.

Numerical investigation on the effect of impeller axial position on hemodynamics of an extracorporeal centrifugal blood pump.

Extracorporeal centrifugal blood pumps are used to treat cardiogenic shock. Owing to the imbalanced excitation or initial assembly configurations, the variation in the impeller axial position has the potential to affect the blood pump performance. This study compared the hydrodynamics and hemolysis outcomes at different impeller axial positions via numerical simulations. The result shows that pressure difference of the blood pump decreased with increasing impeller axial position, with decreasing by 4.5% at a flow rate of 2 L/min. Under axial impeller motion close to the top pump casing, average wall shear stress and scalar shear stress reached their maximum values (64.2 and 29.1 Pa, respectively). The residence time in the impeller center hole and bottom clearance were extended to 0.5 s by increasing impeller axial position. Compared to the baseline blood pump, hemolysis index increased by 12.3% and 24.3% when impeller axial position is 2.5 and 4.0 mm, respectively. As a novelty, the findings reveal that the impeller axial position adversely affects hemolysis performance when the impeller is close to the pump casing. Therefore, in the development process of centrifugal blood pumps, the optimal axial position of the impeller must be defined to ensure hemodynamic performance.

Synthesis and biological evaluation of thiazolidine-2-thione derivatives as novel xanthine oxidase inhibitors.

Xanthine oxidase (XO) is a key enzyme in the generation and development of hyperuricemia. Thiazolidine-2-thione, a typical heterocyclic compound, have been widely used in the field of drug synthesis. In this study, a series of novel thiazolidine-2-thione derivatives were synthesized as XO inhibitors, and the XO inhibitory potencies of obtained compounds were evaluated by in vitro enzyme catalysis. The result shown that compound 6k behaved the strongest XO inhibitory activity with an IC50 value of 3.56 µmol/L, which was approximately 2.5-fold more potent than allopurinol. The structure-activity relationship revealed that the phenyl-sulfonamide group was indispensable for thiazolidine-2-thione derivatives to produce XO inhibitory activity. The enzyme inhibition kinetics analyses confirmed that compound 6k exerted a mixed-type XO inhibition. Additionally, the molecular docking results suggested that the 4-fluorophenyl-sulfonyl moiety could interact with Gly260 and Ile264 in the innermost part of the active pocket through 2 hydrogen bonds, while the thiazolidinethione moiety could form two hydrogen bonds with Glu263 and Ser347 in hydrophobic pockets. In summary, the results described above suggested that compound 6k could be a valuable lead compound for the treatment of hyperuricemia as a novel XO inhibitor.

Discovery of 2H-chromone-4-one based sulfonamide derivatives as potent retinoic acid receptor-related orphan receptor γt inverse agonists.

Retinoic acid receptor related orphan receptor γt (RORγt), identified as the essential functional regulator of IL-17 producing Th17 cells, is an attractive drug target for treating autoimmune diseases. Starting from the reported GSK2981278 (Phase II), we structurally modified and synthesized a series of 2H-chromone-4-one based sulfonamide derivatives as novel RORγt inverse agonists, which significantly improved their human metabolic stabilities while maintaining a potent RORγt inverse agonist profile. Efforts in reducing the lipophilicity and improving the LLE values led to the discovery of c9, which demonstrated potent RORγt inverse agonistic activity and consistent metabolic stability. During in vivo studies, oral administration of compound c9 exhibited a robust and dose-dependent inhibition of IL-17A cytokine expression and significantly lessened the skin inflammatory symptoms in the mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that c9 can suitably occupy the active pocket, and the introduction of the morpholine pyridine group can interact with Leu396, His479, and Cys393. Thus, compound c9 was selected as a preclinical compound for treating Th17-driven autoimmune diseases.

Discovery of Chromane-6-Sulfonamide Derivative as a Potent, Selective, and Orally Available Novel Retinoic Acid Receptor-Related Orphan Receptor γt Inverse Agonist.

Interleukin-17 (IL-17) is a proinflammatory cytokine that plays a dominant role in inflammation, autoimmunity, and host defense. RORγt is a key transcription factor mediating T helper 17 (Th17) cell differentiation and IL-17 production, which is able to activate CD8+ T cells and elicit antitumor efficacy. A series of sulfonamide derivatives as novel RORγt inverse agonists were designed and synthesized. Using GSK2981278 (phase II) as a starting point, we engineered structural modifications that significantly improved the activity and pharmacokinetic profile. In animal studies, oral administration of compound d3 showed a robust and dose-dependent inhibition of the IL-17A cytokine expression in a mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that the compound d3 occupied the active pocket suitably. Thus, compound d3 was selected as a clinical compound for the treatment of Th17-driven autoimmune diseases.

The complete mitochondrial DNA sequence of Yimeng black goat (Capra hircus) and its potential application in mutton discrimination.

Yimeng black goat is one of the national breeds of geographical indication in China and is one of the key protected local livestock and poultry breeds of Shandong province. The complete mitochondrial genome sequence of Yimeng black goat was investigated in this study (GenBank accession no. MT134111). The mitogenome (16,640 bp) consisted of a non-coding control region (D-loop region), two ribosomal RNA (rRNA) genes, 13 protein-coding genes (PCGs), and 22 transfer RNA (tRNA) genes. The complete mitochondrial genome sequence and the neighbour-joining tree of the Yimeng black goat would contribute to further study in genetic mechanism and phylogenomic research of goats.

Effect of PA-MSHA vaccine on plasma phospholipids metabolic profiling and the ratio of Th2/Th1 cells within immune organ of mouse IgA nephropathy.

Phospholipids as a class of important constituents in the biomembranes have been paid increasing attention in many fields. IgA nephropathy is now generally known to be the most common form of primary glomerulonephritis in the world. However, phospholipids metabolism in IgA nephropathy was not clear. Until recently, there was no effective treatment available for patients with IgA nephropathy. In this paper, effect of PA-MSHA vaccine on plasma phospholipid metabolic profile of mouse IgA nephropathy was investigated using high performance liquid chromatography/mass spectrometry (HPLC/MS) and principal components analysis (PCA). Female Balb/c mice were divided into four groups: model group, control group, PA-MSHA treatment group and medicine control group (dipyridamole+common threewingnut root). The experimental IgA nephropathy model was established by the immunity combination method of oral BSA and injection of SEB. It was found that combination of LC/MS technology with PCA can be successfully applied to phospholipids profile analysis, clearly classify the model group and normal group, and PA-MSHA treatment group is closer to the normal control group than medicine control group. The result showed that Th(2)/Th(1) (=CD(4)(+)CD(30)(+)/CD(4)(+)CD(30)(-)) of the model group is 20.70+/-3.57, which is significantly higher than that of the control group (1.34+/-0.14) (P<0.001). The Th(2)/Th(1) ratio of the PA-MSHA treatment group and the medicine control group are lower than that of the model group (P<0.01). It is suggested that mouse IgA nephropathy has the phospholipids metabolic abnormality, PA-MSHA vaccine cannot only regulate the abnormal phospholipids metabolism mouse with the IgA nephropathy, but also correct the over unbalance of Th(2)/Th(1) proportion.

Simultaneous analysis of microsatellite instability and loss of heterozygosity by capillary electrophoresis with a homemade kit.

Microsatellite instability (MSI) and loss of heterozygosity (LOH), the alteration in length and strength of short tandem repeat sequences are an important molecular characteristic of many human tumors. MSI and LOH analysis has become an attractive method for diagnostic and tumor research purposes. A method for the simultaneous analysis of MSI and LOH at the five microsatellite loci (BAT-26, D17S261, D3S1283, D2S123 and D3S1611) was developed employing a cheap homemade kit to replace the expensive commercial kit on ABI 310 capillary genetic analyzer. After studying the effect of temperature and urea denaturant on microsatellite analysis, 8 mol/L urea and 60 degrees C were selected for assessing accurately fragment size of microsatellite alleles. Based on this method, 52 sporadic gastric cancers were screened, and MSI and LOH, at least one locus was observed in 15 of 52 (28.8%) patients. Moreover, it is found that a statistically significant association exists between MSI and LOH and tumor-differentiated level.

Parity and litter size effects on maternal behavior of Small Tail Han sheep in China.

The effects of parity and litter size on maternal behavior of Small Tail Han sheep was investigated at Linyi University, China. Sixty-eight ewes were observed from parturition to weaning. Continuous focal animal sampling was used to quantify the duration of maternal behaviors. Ewe feces were collected every 2 days and estradiol concentration was measured with an enzyme immunoassay kit. All lambs were weighed 24 h after parturition and again at 35 days of age. Parity increased sucking, following, grooming, low-pitched bleat, head-up and udder-refusal behavior and decreased aggressive behavior (P < 0.01, P < 0.01, P < 0.05, P < 0.05, P < 0.05, P < 0.05, P < 0.01, respectively), and litter size showed significant effect on sucking, following and low-pitched bleat behavior (P < 0.05, P < 0.01, P < 0.05, respectively). The lambs of multiparous ewes were significantly heavier than primiparous ewes at birth (P < 0.01) and were significantly heavier at weaning age (P < 0.01). Similar results were founded for birth weight and weaning weight gain in litter size (P < 0.01, P < 0.01, respectively). Estradiol concentration in feces was higher in multiparous ewes than primiparous ewes. Parity and litter size may have effects on maternal behavior during lactation. Ewes that have 2-3 lambs may be more suitable for production of Small Tail Han sheep in China.

Etomidate Mitigates Lipopolysaccharide-Induced CD14 and TREM-1 Expression, NF-κB Activation, and Pro-inflammatory Cytokine Production in Rat Macrophages.

This study was aimed at investigating the effect of etomidate on the viability of rat macrophages and the function of lipopolysaccharide (LPS)-stimulated macrophages as well as the potential mechanisms. Rat macrophages were isolated and treated with different doses of etomidate for 24 h, and their viability was determined by the CCK-8 assay. Furthermore, macrophages were treated with, or without, 1 µg/ml of LPS, and/or 2.5 or 5 µM etomidate in the presence or absence of a TREM-1 inhibitor (LP17, 100 ng/ml), and the levels of TNF-α, IL-6, CD14, and TREM-1 in the different groups of cells were determined by quantitative RT-PCR, ELISA, and Western blot assays. The levels of NF-κB activation in the different groups of cells were analyzed by an electrophoretic mobility shift assay (EMSA). Etomidate at 31.25 µM or a low dose did not affect the viability of rat macrophages, while etomidate at higher doses reduced the viability of macrophages in vitro. Treatment with 2.5 or 5 µM etomidate or with LP17 alone did not affect the levels of TNF-α, IL-6, CD-14, and TREM-1 in macrophages. Treatment with etomidate significantly mitigated LPS-stimulated TNF-α, IL-6, CD-14, and TREM-1 expression (p < 0.05 for all) and inhibited LPS-induced NF-κB activation in macrophages in vitro. However, treatment with both etomidate and LP17 did not enhance the inhibitory effects in macrophages. Hence, etomidate mitigates LPS-up-regulated pro-inflammatory cytokine production and inhibits LPS-enhanced CD14 and TREM-1 expression and NF-κB activation in macrophages.

The pituitary adenylate cyclase-activating polypeptide (PACAP) protects adrenal function in septic rats administered etomidate.

BACKGROUND: Both hyperinflammation during sepsis and etomidate can suppress adrenal function. In this study, we explored whether treatment with pituitary adenylate cyclase-activating polypeptide (PACAP) relieves adrenal suppression in cecal ligation and puncture (CLP)-induced septic rats. MATERIALS AND METHODS: Female Sprague-Dawley rats were randomly divided into five groups (n=7 per group), including the sham group, sepsis group (CLP group), sepsis and etomidate group (CLP+ETO group), PACAP group, and etomidate alone group (ETO group). Rats were sacrificed on the third day of sepsis, and blood and adrenal gland samples were obtained for further testing. RESULTS: The PACAP reduced the apoptosis rate of adrenal cells and peripheral lymphocytes, improving adrenal function, inhibiting the secretion of interferon gamma (IFN-γ) from peripheral lymphocytes, and slightly relieving the suppression of the adrenal function induced by the injection of etomidate in sepsis. CONCLUSION: In septic conditions, the PACAP protects the adrenal gland by regulating peripheral inflammation, which slightly relieves the toxic effects of etomidate on adrenal function.

Etomidate inhibits nuclear factor-κB through decreased expression of glucocorticoid receptor in septic rats.

The present study aimed to investigate the effect of etomidate administered prior to or following cecal ligation and puncture (CLP) on the expression of glucocorticoid receptor (GR) and lymphocyte apoptosis in septic rats. Right jugular vein catheterization was performed on female Sprague­Dawley rats under isoflurane anesthesia, and CLP surgery was performed to induce sepsis 3 days following catheterization. The rats were randomly divided into five groups. All groups were infused with 2 ml of either etomidate or 5‰ dimethyl sulfoxide (DMSO) at 1 ml/h for 2 h from 6 h post­surgery. The sham group received abdominal sham surgery and infusion with DMSO; the CLP control group received infusion with DMSO. Treatment group A received infusion with 2 mg/kg etomidate; group B received 0.6 mg/kg etomidate following CLP and an infusion of 2 mg/kg etomidate. Group C received 0.6 mg/kg etomidate 24 h prior to CLP and post­surgical etomidate infusion. The 10­day survival rates of the rats in the CLP, A, B and C groups were 60, 50, 55 and 40%, respectively. The serum mRNA expression levels of tumor necrosis factor­α, GR and glucocorticoid­induced leucine zipper were detected by reverse transcription­quantitative polymerase chain reaction, the abundance of inhibitor of nuclear factor (NF)-κB­α was measured by western blotting, and the apoptotic rates of the splenic lymphocytes were determined using flow cytometry. The results suggested that etomidate inhibited NF­κB by decreasing the expression of GR in the septic rats. The increased apoptosis of lymphocytes induced by etomidate may lead to a poor outcome during sepsis.

Clinical significance and prognostic value of urinary nucleosides in breast cancer patients.

OBJECTIVE: Thirteen urinary nucleosides, primarily degradation products of tRNA, were evaluated as potential tumor markers for breast cancer patients. DESIGN AND METHODS: The micellar electrokinetic chromatography (MEKC) method has been used to analyze the urinary nucleosides in 41 healthy controls, 20 patients with benign breast tumors, and 26 breast cancer patients. RESULTS: Urinary nucleoside concentrations of breast cancer patients were found to increase significantly compared to those of patients with benign breast tumors and healthy controls. By using 13 nucleoside concentrations as data vectors for principal component analysis (PCA), 73% (19/26) of breast cancer patients were correctly identified from healthy controls, while only 20% (4/20) of patients with benign breast tumors were indistinguishable from breast cancer patients. The mean level of all forms of urinary nucleosides in patients with metastatic breast cancer was higher than that in patients with primary breast cancer. The levels of modified nucleosides tended to decrease and return to normal after surgery. CONCLUSION: The results indicate that urinary nucleosides may be useful as tumor markers for breast cancer.

Effect of Helicobacter pylori infection on p53 expression of gastric mucosa and adenocarcinoma with microsatellite instability.

AIM: To investigate the relationship between Helicobacter pylori (H pylori) infection, microsatellite instability and the expressions of the p53 in gastritis, intestinal metaplasia and gastric adenocarcinoma and to elucidate the mechanism of gastric carcinogenesis relating to H pylori infection. METHODS: One hundred and eight endoscopic biopsies and gastric adenocarcinoma were available for the study including 33 cases of normal, 45 cases of gastritis, 30 cases of intestinal metaplasia, and 46 cases of gastric adenocarcinoma. Peripheral blood samples of these patients were also collected. H pylori infection and p53 expressions were detected by means of streptavidin-peroxidase (SP) immunohistochemical method. Microsatellite loci were studied by PCR-SSCP-CE using the markers BAT-26, D17S261, D3S1283, D2S123, and D3S1611. MSI was defined as the peak shift in the DNA of the gastric tissue compared with that of the peripheral blood samples. Based on the number of mutated MSI markers, specimens were characterized as high MSI (MSI-H) if they manifested instability at two or more markers, low MSI (MSI-L) if unstable at only one marker, and microsatellite stable (MSS) if they showed no instability at any marker. RESULTS: H pylori infection was detected in the samples of gastritis, intestinal metaplasia, and gastric adenocarcinoma and the infection frequencies were 84.4%, 76.7%, and 65.2%, respectively, whereas no H pylori infection was detected in the samples of normal control. There was a significant difference in the infection rates between gastritis and carcinoma samples (P = 0.035). No MSI was detected in gastritis samples, one MSI-H and two MSI-L were detected among the 30 intestinal metaplasia samples, and 12 MSI-H and 3 MSI-L were detected in the 46 gastric carcinomas. In those gastric carcinomas, the MSI-H frequency in H pylori-positive group was significantly higher than that in H pylori-negative group. No p53 expression was detected in the normal and gastritis samples from dyspeptic patients. P53-positive immunohistochemical staining was detected in 13.3% of intestinal metaplasia samples and in 43.5% of gastric carcinoma samples. The levels of p53 in H pylori-positive samples were higher than those in the negative group when the carcinoma samples were subdivided into H pylori-positive and -negative groups (P = 0.013). Eight samples were detected with positive p53 expression out of the 11 MSI-H carcinomas with H pylori infection and no p53 expression could be seen in the H pylori-negative samples. CONCLUSION: H pylori affect the p53 pattern in gastric mucosa when MMR system fails to work. Mutations of the p53 gene seem to be an early event in gastric carcinogenesis.

Urinary nucleosides as biological markers for patients with colorectal cancer.

AIM: Fourteen urinary nucleosides, primary degradation products of tRNA, were evaluated to know the potential as biological markers for patients with colorectal cancer. METHODS: The concentrations of 14 kinds of urinary nucleosides from 52 patients with colorectal cancer, 10 patients with intestinal villous adenoma and 60 healthy adults were determined by column switching high performance liquid chromatography method. RESULTS: The mean levels of 12 kinds of urinary nucleosides (except uridine and guanosine) in the patients with colorectal cancer were significantly higher than those in patients with intestinal villous adenoma or the healthy adults. Using the levels of 14 kinds of urinary nucleosides as the data vectors for principal component analysis, 71% (37/52) patients with colorectal cancer were correctly classified from healthy adults, in which the identification rate was much higher than that of CEA method (29%). Only 10% (1/10) of patients with intestinal villous adenoma were indistinguishable from patients with colorectal cancer. The levels of m1G, Pseu and m1A were positively related with tumor size and Duke's stages of colorectal cancer. When monitoring the changes in urinary nucleoside concentrations of patients with colorectal cancer associated with surgery, it was found that the overall correlations with clinical assessment were 84% (27/32) and 91% (10/11) in response group and progressive group, respectively. CONCLUSION: These findings indicate that urinary nucleosides determined by column switching high performance liquid chromatography method may be useful as biological markers for colorectal cancer.

Pretreatment with low dose etomidate prevents etomidate-induced rat adrenal insufficiency by regulating oxidative stress-related MAPKs and apoptosis.

Etomidate is frequently used as an anesthetic and sedation agent in the clinic setting. This study determined that a low-dose pre-infusion followed by a continuous dose infusion of etomidate could reduce etomidate-induced adrenal gland insufficiency. Sixty adult male Wistar rats were used, with six rats per group. Based on preliminary experiments, 0.6mg/kg etomidate was selected as the low dose for this study. Oxidative stress and apoptosis-related proteins in the adrenal glands were assayed using Western blot, and serum levels of CORT and 11ß-hydroxylase were detected using ELISA. Pretreatment with a single bolus of low dose etomidate significantly increased the levels of CORT and 11ß-hydroxylase as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathioneperoxidase (GPx) in the adrenal glands, but reduced nitric oxide (NO) production when compared to the positive group. Furthermore, Western blot data showed that pretreatment with low dose etomidate increased extracellular signal-regulated kinase1/2 (ERK1/2), CREB and bcl-2 activation, but suppressed the p-p38, c-JunN-terminal kinase (JNK), inducible NO synthase (iNOS), cleaved-caspase3, cleaved-poly-ADP-ribose polymerase (PARP), bax, and AKT activation. The ERK inhibitor PD98059 and the p38MAPK inhibitor SB203580 abolished the protective effect of low dose etomidate pretreatment. These data demonstrated that pretreatment with low dose etomidate attenuated etomidate-induced adrenal insufficiency to rat adrenal glands. Oxidative stress-related MAPKs and apoptosis proteins might be responsible for mediating the etomidate preconditioning effect in rats.