OBJECTIVE To investigate the anti-fatigue effect of chicory polysaccharide(CP)on mice exposed to simulated hypobaric hypoxia.METHODS Male C57BL/6J mice were randomly divided into the control group,model group,model+CP 150,300 and 600 mg·kg-1 groups.The control and model groups were given normal saline,while the CP groups were given drugs of different doses.After a 14 d pre-administration period,all the mice except the control group were exposed to a simulated alti-tude of 7 000 m in a hypobaric and hypoxic animal experimental chamber.After 7 d,a treadmill fatigue test was conducted to assess exercise endurance.The body weight and organ indexes were evaluated.The pathological changes in organs and tissues were observed via HE staining.The levels of fatigue-related and oxidative stress-related indicators were measured.The expression levels of phosphorylated AMP-activated protein kinase(p-AMPK),peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC-1α),and cytochrome c oxidase Ⅳ(COXⅣ)were determined using Western blotting anal-ysis.RESULTS Compared with model group,exercise endurance was significantly enhanced,body weight and organ indexes improved,and pathological damage to the lung,liver and skeletal muscle mitigated in the model+CP 600 mg·kg-1 group.Compared with model group,the model+CP 600 mg·kg-1 group had the contents of serum lactate and blood urea nitrogen reduced,but the contents of glycogen and the activity of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in the liver and skeletal muscle were increased.The malondialdehyde content was lowered,but the expressions of p-AMPK,PGC-1α,and COXⅣ in skeletal muscle were significantly increased.CONCLUSION CP can alleviate altitude-induced fatigue by reducing the metabolite accumulation,increasing glycogen storage,and lowering oxidative stress levels.The underlying mechanism may involve the activation of the AMPK/PGC-1αsignaling pathway.

OBJECTIVE To study the effects of Ro 64-6198,a selective nociceptin/orphanin FQ receptor(NOPR)agonist,on heroin self-administration and drug-seeking behavior in rats.METHODS Rats were trained to self-administer heroin intravenously at a dose of 0.05 mg·kg-1 under a fixed ratio 1(FR1)reinforcement schedule.Heroin motivation was assessed using a progressive ratio(PR)schedule.Firstly,a stable heroin self-administered rat model was established before the effects of Ro 64-6198 on heroin rewarding under the FR1 schedule were observed.After three days of self-administration recovery training,the effects of Ro 64-6198 on heroin reward motivation were observed under the PR3-4 schedule.Following extinction,the reinstatement of heroin seeking induced by either conditioned cues or heroin priming was evaluated in rats withdrawn from self-administration.The expressions of cAMP response element-binding protein(CREB)and brain-derived neurotrophic factor(BDNF)in the ventral tegmental area(VTA)were analyzed using Western blotting,while the expression of the NOPR in neurons in the VTA was examined through immunofluorescence staining.RESULTS Pretreatment with 3 mg·kg-1 Ro 64-6198 significantly reduced active responses and heroin infusions during FR1 testing,as well as decreased breakpoints,indicating reduced motivation under the PR schedule.At a dose of 1 mg·kg-1,Ro 64-6198 markedly attenuated the reinstatement of heroin-seeking behavior induced by conditioned cues or heroin priming.Furthermore,the administration of SB-612111,an NOPR antagonist,blocked the inhibitory effects of Ro 64-6198 on cue-induced heroin-seeking,although SB-612111 alone had no effect on heroin-seeking behavior.Ro 64-6198 treatment also suppressed the reduction of both phos-phorylated CREB(p-CREB)and BDNF levels in the VTA and the decreased expression of NOPR and p-CREB in dopaminergic neurons of the VTA.CONCLUSION These results demonstrate that Ro 64-6198 can mitigate heroin-seeking behavior through NOPR activation and CREB/BDNF pathway in the VTA.This study is expected to offer evidence for its potential as a clinical treatment for heroin addiction and relapse.

OBJECTIVE To establish an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for determination of dexmedetomidine(DEX)in plasma of beagle dogs and evaluate the pharmacokinetics and sedation after nasal,buccal and sublingual mucosal admin-istration.METHODS A UPLC-MS/MS method was established and validated for dertermination of DEX in plasma of beagle dogs.DEX was administered to the nasal cavity,buccal and sublingual mucous membranes of beagle dogs,respectively.Blood samples were collected at different time points.The plasma concentration of DEX was measured by the established UPLC-MS/MS method.Pharmacokinetic parameters were fitted by Phoenix software and the sedative effect at different mucous membrane sites was evaluated in conjunction with behavioral and Ramsay scores.RESULTS The linearity of DEX was fine within the range of 0.05-100 μg·L-1(r>0.999),which was validated methodologically to meet the requirements of quantitative detection.The plasma concentration of the drug peaked the fastest with nasal administration.Tmax was 0.25 h,Cmax(4.43±1.19)μg·L-1,and the AUC0-6h was(8.92±2.07)μg·h·L-1,compared with 0.92 and 1 h,(2.87±0.69),(2.70±0.41)μg·L-1,and(7.99±1.77),(7.01±2.09)μg·h·L-1 with buccal and sublingual administration.Nasal administration had the fastest onset at 7 min,with a Ramsay score of 4,and sedation lasted for 36 min,compared with 33 and 35 min,and 38 and 37 min for buccal and sublingual administration.CONCLUSION The proposed method is sensitive,reliable and applicable to quantitative analysis of DEX in plasma of beagle dogs.Administration of DEX to the nasal cavity mucosa has a faster onset and a better sedative effect than to the buccal and sublingual mucosa.

OBJECTIVE To investigate the biodistribution of lipid nanoparticles(LNPs)with different surface charges and different particle sizes in mice.METHODS LNPs were prepared using microfluidic technology by incorporating positively charged phospholipids,negatively charged phospholipids,ioniz-able phospholipids,and neutral phospholipids into the formulation to create LNPs with corresponding surface charges.The particle size of the LNPs was controlled by polyethylene glycol(PEG)modifica-tion and measured using dynamic light scattering(DLS)and transmission electron microscopy(TEM),while the surface charge was analyzed using a zeta potential analyzer.The LNPs were labeled with a fluorescent dye,and the mice were intravenously injected with 0.625 μmol·kg-1 of LNPs.At 1,4,12 and 24 h post-injection,the brain,heart,livers,spleen,lungs and kidneys were collected.The fluorescence distribution in different organs was detected using an in vivo imaging system to reflect the distribution of LNPs in various organs.RESULTS Particle size analysis showed that,except the ionizable lipid nanoparticles without PEG modification(LNP-MC3),which had a particle size>200 nm,the particle sizes of positively charged LNPs without PEG modification(LNP-Pos),PEG-modified positively charged LNPs(LNP-Pos-P),PEG-modified neutral LNPs(LNP-Neu-P),PEG-modified ionizable LNPs(LNP-MC3-P),and PEG-modified negatively charged LNPs(LNP-Neg-P)were all<200 nm.Zeta potential analysis revealed that the surface charges of the LNPs were the highest in LNP-Pos,followed by LNP-Pos-P,LNP-MC3-P,LNP-Neu-P,LNP-MC3 and LNP-Neg-P.In vivo imaging results indicated that LNP-Pos-P,LNP-Pos and LNP-MC3-P were primarily distributed in the livers,lungs and kidneys,respectively,while LNP-Neu-P and LNP-Neg-P in the livers,kidneys,and lungs,respectively.The distribution of LNP-MC3-P in the brain,heart,spleen and kidneys peaked at 12 h post-injection,but at 24 h in the livers.The distribution of LNP-Pos-P in the lungs peaked at 1 h post-injection.CONCLUSION LNPs are primarily distributed in the livers.Surface charges influence the second most highly-distributed organs.LNP-Pos-P and LNP-MC3-P are the second most highly-distributed in the lungs,and LNP-Neu-P and LNP-Neg-P in the kidneys.

OBJECTIVE To investigate the mechanisms of adrenal dysfunction among adult offspring rats caused by prenatal ethanol exposure(PEE)aggravated by high-fat diet(HFD)and unpredictable chronic stress(UCS).METHODS Pregnant rats were randomly divided into the control group(saline,ig,once)and PEE group(4 g·kg-1,ig,once)from gestational day(GD)11 until delivery.At postnatal week 4(PW4),offspring rats from the control group and PEE group were randomly assigned to three sub-groups:the normal diet(ND)group,HFD group,and HFD-UCS group(n=20 per subgroup,at an equal male-to-female ratio).The rats in each group were given a corresponding diet until PW24.The HFD-UCS group received HFD until PW24,with additional UCS treatment initiated at PW21 and continued for 3 weeks.Serum adrenocorticotropic hormone(ACTH)levels were measured by radioimmunoassay,and corticosterone(CORT)levels were quantified via enzyme-linked immunosorbent assay(ELISA).Adrenal mRNA expressions of steroidogenic factor 1(Sf1),steroidogenic acute regulatory protein(Star),cyto-chrome P450 cholesterol side chain cleavage(P450scc),3β-hydroxysteroid dehydrogenase(3β-Hsd),steroid 21-hydroxylase(P450c21),steroid 11β-hydroxylase(P450c11),11β-hydroxysteroid dehydrogenase type 1(11β-Hsd1),11β-Hsd 2,mineralocorticoid receptor(Mr),glucocorticoid receptor(Gr),insulin-like growth factor 1(Igf1),IGF1 receptor(Igf1r),and serine/threonine kinase 1(Akt1)were determined using real-time quantitative PCR.Protein expressions of Akt1 and phosphorylated Akt1(p-Akt1)were analyzed via immunohistochemistry.RESULTS In male offspring,HFD/PEE significantly reduced serum ACTH and CORT levels,downregulated Star,P450scc,3β-Hsd and P450c11 mRNA,decreased 11β-Hsd1 mRNA expressions and 11β-Hsd1/11β-Hsd2 ratio,but increased Igf1,Igf1r mRNA,and p-Akt1 protein.Conversely,HFD-UCS/PEE elevated ACTH,CORT,P450scc,3β-Hsd and P450c11 mRNA,increased 11β-Hsd1 and 11β-Hsd1/11β-Hsd2 ratio while suppressing Igf1 mRNA,and p-Akt1 protein.In females,HFD/PEE decreased ACTH but upregulated Igf1,Akt1 mRNA,and p-Akt1 protein.HFD-UCS/PEE increased ACTH,CORT,Sf1,Star,P450scc and P450c11 mRNA,and 11β-Hsd1/11β-Hsd2 ratio,but reduced lgf1 and Igf1r mRNA.CONCLUSION HFD/UCS can aggravate PEE-induced adrenal dysfunction in adult offspring.The adrenal"GC-IGF1 axis"is an endocrine negative feedback one,and its decompensation may increase the susceptibility of a wide range of GC-related adult chronic diseases,such as diabetes.

OBJECTIVE To study the effects of ethanol on markers of gastric stem cells and epithe-lial cells,and explore the related signal pathways for stem cells differentiation in a mouse gastric mucous injury model.METHODS Male C57BL/6 mice were randomly divided into normal control and ethanol groups.The mice in the control group were given normal drinking water while those in the ethanol group were gavaged with 10 ml·kg-1 50%(V/V)ethanol on day 1,and drinking water containing 10%(V/V)ethanol was given on day 2-9.On the 10th day,stomach tissues were collected.HE staining was used to detect pathological changes in the stomach.Immunohistochemistry(IHC)staining was used to detect changes of such cell markers as mucin 5AC,H+/K+ATPase β and pepsin C.Immunofluorescence(IF)staining was employed to analyze changes in expression of cell markers such as H+/K+ATPase β,pepsin C and gastrin.ELISA assay was used to measure gastrin,somatostatin and interleukin 1β(IL-1β)concentrations in gastric tissue homogenates.Flow cytometry was adopted to measure the number of leucine rich repeat containing G protein-coupled receptor 5 positive(LGR5+)stem cells in gastric glands.Organoids was constructed to characterize stem cell activity.RNA sequencing and bioinformatics analysis were conducted to analyze the inflammatory pathways and differentiation signaling pathways during mice gastric mucous injury.RESULTS H&E results showed multifocal necrosis of the mucosal layer appeared in the ethanol group,accompanied by pyknosis,lysis and detachment of mucosal epithelial cells and gastric gland cells.IHC results showed decreased expressions of mucin 5AC and increased expressions of H+/K+ATPase β and pepsin C.IF results revealed increased expressions of H+/K+ATPase β,pepsin C,and gastrin after ethanol treatment.ELISA results demonstrated significant increases in gastrin,somatostatin and IL-1β levels in gastric tissues of the ethanol group.Flow assay results suggested that the number of LGR5+stem cells significantly decreased in ethanol treated gastric tissues.Stem cells from stomach tissues treated with ethanol did not grow into organoids.RNA sequencing and bioinformatics analyses revealed enrichment of TNF,NF-κB and Notch pathways in the ethanol group.CONCLUSION Administration of 50%ethanol solution on day 1,followed by continuous admin-istration of 10%ethanol solution on day 2-9 can induce histopathological injury to the gastric gland and stem cells,and an increase in epithelial cells.These changes may be related to the up-regulation of inflammatory pathways and Notch signaling pathways triggered by ethanol.

Commonly used anesthetic sedatives(opioids,benzodiazepines,ketamine,propofol,etc.)share the risk of inducing respiratory depression,and their multi-target mechanism of action pres-ents significant heterogeneity.Opioids inhibit the rhythmic activity of the respiratory center of the medulla bulbar(such as the PreB?tzinger complex and parbrachial nucleus)by activating both the μ-opioid receptor and the G-protein-gated inwardly-rectifying potassium channel and β-arrestin signaling pathway,resulting in decreased respiratory frequency and amplitude.Benzodiazepines enhance inhibitory neurotransmis-sion mediated by γ-aminobutyric acid receptors,reduce the sensitivity of chemoreceptors to PaCO2 and PaO2,and lead to a decreased tidal volume and upper airway obstruction.Ketamine inhibits respiratory drive and respiratory muscle function by blocking N-methyl-D-aspartic acid receptors and indirectly affecting the μ-opioid receptor.In addition,propofol inhibits pre-expiratory neuronal activity and relaxes upper airway muscles by activating the GABAA receptor β3 subunit.Currently,specific antagonists(naloxone/flumazenil)and respiratory stimulants(doxapram)are clinically used to treat respiratory depression,but they have defects such as short duration of action and insufficient specificity.The devel-opment of novel stimulants targeting μ-opioid receptor agonists and the D-serine release pathway of astrocytes,as well as broad-spectrum antidotes based on"molecular cage"technology,has become a new sphere of research that aims at precisely reversing respiratory depression while preserving analgesic and sedative effects.This article reviews the biological mechanisms of respiratory depression caused by sedative hypnotic anesthetic drugs,explores the advantages and disadvantages of treatments currently availabe,and proposes new strategies for improving respiratory depression in the future.

Extrasynaptic γ-aminobutyric acid type A(GABAA)receptors are a class of inhibitory neurotransmitter receptors that are distributed in non-synaptic structures such as cell bodies and dendrites.Extrasynaptic GABAA receptors are heteropentamers usually containing δ-subunit.Changes of δ-subunit expressions can be observed in model animals of postpartum depression and premenstrual syndrome,and δ-/-or δ+/-mice exhibit behavioral phenotypes of postpartum depression,suggesting that extrasynaptic GABAA receptors are involved in the pathogenesis of related diseases.The present review is concerned with the relationship between extrasynaptic GABAA receptors and postpartum depression as well as premenstrual syndrome in general,and the advances in research on drugs targeting extrasynaptic GABAA receptors for the treatment of these two conditions in particular.The article highlights the value of extrasynaptic GABAA receptors as a therapeutic target for female mood disor-ders,and may provide a reference for the development and application of related drugs.

The intestine in a hypoxic state is an essential physiological organ,and its primary func-tions include digestion,absorption,excretion,hormone secretion,and providing barrier and immune protec-tion.Hypoxia-inducible factor-2α(HIF-2α)represents one of the important physiologicalregulators for the intestine,partaking in the regulation of iron homeostasis,oxygen homeostasis and energy metabo-lism in the intestinal environment.Recent studies have shown that HIF-2α is closely associated with the onset and progression of various intestinal-related diseases,including iron-relatedblood diseases,inflam-matory bowel disease(IBD),colorectal cancer(CRC),and obesity-related metabolic diseases.Thus,HIF-2α may be a novel target for the treatment.HIF-2α is currently a hot topic in drug development,and numerous studies have revealed that it has therapeutic potential for intestinal-related diseases.HIF-2α is a key transcription factor that regulates intestinal iron absorption and systemic iron homeostasis.Aberrant expression of HIF-2α has been closely linked to various hematological disorders associated with iron metabolism dysregulation.In the pathological hypoxic microenvironment of the intestine,sustained activation of HIF-2α induces inflammatory response and impairs epithelial barrier function,thereby exacerbating the progression of IBD.Within the tumor microenvironment,HIF-2α contributes to CRC progression through multiple mechanisms,including metabolic reprogramming,angiogenesis,enhanced prolifera-tion,migration,and invasion of tumor cells,as well as inflammation,iron accumulation,and immune evasion.Moreover,HIF-2α is involved in the regulation of obesity,insulin resistance,and glucose-lipid metabolism via the gut-liver axis.Although seven HIF-2α modulators have been approved for clinical use,adverse effects such as anemia and thrombosis remain concerns.Therefore,developing next-generation HIF-2α-targeted strategies with improved specificity and safety profiles is critical to future research.This article is an overview of the recent advancements in understanding the role and mecha-nisms of HIF-2α in intestinal health and associated diseases while analyzing the challenges to develop-ment and application of HIF-2α modulators in the future,in hopes of offering novel therapeutic avenues for intestinal-related ailments.

OBJECTIVE To investigate the effects of potassium channel Kv1.3knockout(Kv1.3 KO)on neurological dysfunction and neuroinflammation in C57BL/6 mice following traumatic brain injury(TBI).METHODS C57BL/6 mice and homozygous Kv1.3 KO C57BL/6 mice were subjected to the classic controlled cortical impact model to establish a TBI model.The experimental groups included the sham surgery group,C57BL/6 TBI model group(TBI group),and a Kv1.3 KO C57BL/6 TBI model group(TBI+Kv1.3 KO group).At 1,2,and 3 weeks post-modeling,real-time quantitative PCR was used to measure the mRNA expression levels of Kv1.3,interleukin-1β(IL-1β),IL-6,tumor necrosis factor-α(TNF-α),and IL-10 in hippocampal tissues.At 1 and 3 weeks post-modeling,Western blotting was performed to detect Kv1.3 protein expressions in the hippocampus.At 3 weeks post-modeling,Western blotting was used to assess the protein levels of IL-1β,IL-6,TNF-α,and IL-10 in hippocampal tissues.Additionally,immunofluorescence was employed to quantify cells co-labeled with the microglial marker ionized calcium-binding adapter molecule 1(IBA1)and Kv1.3,IL-1β,or TNF-α in the hippocampus.Patch-clamp recordings were conducted to measure Kv1.3 channel currents in primary microglia at 3 weeks post-modeling.Neurological function was evaluated at 1 and 3 weeks post-modeling using the neurological severity score(NSS),pole climbing,and rotarod tests.Cognitive function was assessed at 3 weeks post-modeling via open field,Morris water maze,and Y-maze tests.RESULTS Compared with the sham group,the TBI group exhibited significantly elevated mRNA expression levels of Kv1.3 and IL-1β in the hippocampus at 1,2 and 3 weeks post-modeling,while IL-6 and IL-10 mRNA levels showed no significant changes.Notably,TNF-α mRNA expressions demonstrated a significant increase only at 2 and 3 weeks post-modeling.At 1 and 3 weeks post-modeling,Kv1.3 protein expres-sions in the hippocampus were significantly higher in the TBI group.At 3 weeks post-modeling,hippo-campal IL-1β and TNF-α protein levels were markedly increased in the TBI group,whereas IL-6 and IL-10 protein levels did not change significantly.Moreover,Kv1.3 current density in primary microglia was signifi-cantly enhanced in the TBI group at 3 weeks post-modeling.Immunofluorescence analysis revealed that the number of IBA1-positive microglia co-labeled with Kv1.3,IL-1β,or TNF-α in the hippocampus was significantly larger in the TBI group than in the sham group at 3 weeks post-modeling.Behaviorally,the TBI group exhibited significantly higher NSS scores,lower success rates in full turn attempts,and longer times taken to descend the pole at 1 and 3 weeks post-modeling compared with the sham group.At 3 weeks post-modeling,TBI mice also demonstrated reduced total movement distance in the open field,decreased time spent in the central zone,fewer platform crossings,less time in the target quadrant,and lower spontaneous alternation rates.In contrast,the TBI+Kv1.3 KO group showed signifi-cantly improved outcomes compared with the TBI group:lower NSS scores,higher success rates in full turns,and shorter time taken to descend the pole at 1 and 3 weeks post-modeling.At 3 weeks post-modeling,the TBI+Kv1.3 KO group displayed longer rotarod endurance,increased total movement dis-tance in the open field,more time spent in the central zone,higher platform crossings,greater target quadrant exploration time,and improved spontaneous alternation rates.Furthermore,at 1 and 3 weeks post-modeling,the TBI+Kv1.3 KO group exhibited significantly reduced mRNA expression levels of the inflammatory cytokines IL-1β and TNF-α in the hippocampus compared with the TBI group.CONCLU-SION Potassium channel Kv1.3 knockout mitigates neurological dysfunction and neuroinflammation in C57BL/6 mice following TBI.