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Biomedical subjects

Xuan Zhang

Publications and source records attributed to Xuan Zhang.

At least 19 recordsLinked to original sources
PubMed2026

Pancreatic fat and the risk of future dysglycemia: a systematic review and meta-analysis.

CONTEXT: Pancreatic fat has emerged as a metabolically relevant ectopic fat depot, but its longitudinal association with future dysglycemic outcomes remains incompletely defined. OBJECTIVE: This study aims to evaluate the longitudinal association of pancreatic fat with incident type 2 diabetes (T2D) and glycemic progression, with exploratory narrative synthesis of evidence in lean populations. DATA SOURCES: PubMed, Embase, Web of Science, and the Cochrane Library were searched from inception to March 1, 2026. STUDY SELECTION: Longitudinal observational studies assessing pancreatic fat at baseline and reporting subsequent incident T2D, glycemic progression, or both were included. DATA EXTRACTION: Two reviewers independently screened studies and extracted data. Methodological quality was assessed using the Newcastle-Ottawa Scale. DATA SYNTHESIS: Ten studies were included. In the primary binary meta-analysis (5 studies), higher pancreatic fat burden was associated with incident T2D (pooled effect estimate, 2.56; 95% CI, 1.27-5.14; I2 = 93.3%). Exclusion of 1 influential ultrasound-based study attenuated heterogeneity while preserving the association (pooled effect estimate, 1.45; 95% CI, 1.23-1.73; I2 = 10.2%). A separate continuous analysis (3 studies) also supported an association with incident T2D (1.17; 95% CI, 1.04-1.32; I2 = 79.2%), although exposure scales were not directly comparable. Pancreatic fat was also associated with glycemic progression (2 studies; 1.96; 95% CI, 1.10-3.48; I2 = 73.2%). Exploratory lean-population evidence was limited to 2 analytical contexts, synthesized narratively, and directionally consistent with the overall findings. CONCLUSION: Pancreatic fat was associated with adverse future glycemic outcomes across multiple analytical contexts. These findings support pancreatic fat as a potentially meaningful imaging-derived marker of future dysglycemia, while suggesting that heterogeneity is partly explained by differences in exposure ascertainment.

Humans↗
PubMed2026

Constipation and Psychiatric Disorders: A Bidirectional Mendelian Randomization Study.

BACKGROUND: Observational studies have shown a link between constipation (CN) and psychiatric disorders, including Schizophrenia (SP), Bipolar disorder (BD), Schizoaffective disorder (SD), and Parkinson's disease (PD). However, it is still unknown whether CN affects the occurrence and development of psychiatric disorders or whether psychiatric disorders cause the occurrence and development of CN. Therefore, this study used Mendelian randomization (MR) analysis to evaluate the relationship between CN and psychiatric disorders. METHOD: We used genome-wide association studies (GWAS) to assess the relationship between constipation (N = 411, 623) and four psychiatric disorders, including SP ( N = 77, 096), BD (N = 51, 710), SD ( N = 210, 962), PD (N = 482, 730 ), using bidirectional MR analysis. Inverse variance weighting (IVW), MR Egger (ME) and Weighted median (WM) were used as causal analysis methods. Cochran's Q test, funnel plot, MR Egger intercept test and Leave.one.out analysis were used to detect sensitivity. Confounding factors were analyzed and eliminated by LDtrait to avoid influencing the final MR Analysis result. RESULTS: The results of positive MR analysis indicated that there was no evidence of influence of constipation on SP (OR 1.043, 95%CI 0.946 - 1.149, P value = 0.398), BD (OR 1.114, 95%CI 0.995 - 1.248, P value = 0.062), SD (OR 0.934, 95%CI 0.674 - 1.294, P value = 0.682) and PD (OR 1.118, 95%CI 0.918 - 1.361, P value = 0.269) under gene prediction. Reverse MR analysis suggested that SP (OR 1.030, 95% CI 1.001-1.060, P value = 0.042) had a causal relationship with constipation. BD (OR 0.993, 95% CI 0.962-1.025, P value = 0.664), SD (OR 1.021, 95% CI 0.984-1.059, P value = 0.265) and PD (OR 1.004, 95% CI 0.974-1.035, P value = 0.790) were not associated with CN. CONCLUSION: There was a positive association between SP and CN. CN may have no exact causal relationship with BD, SD and PD, and the interaction mechanism between these diseases needs to be further explored.

Constipation↗
PubMed2026

Transcriptome Analysis, Machine Learning, and Experimental Identification of CDK7 Affecting the Progression of Pregnancy-induced Hypertension by Influencing Macrophage Polarization.

INTRODUCTION: Pregnancy-induced hypertension (PIH) is a severe pregnancy complication characterized by placental insufficiency, abnormal vascular remodeling, and immune dysregulation, but personalized therapeutic markers remain unclear. This study aimed to identify key genes and explore immune mechanisms in PIH using transcriptome analysis, machine learning, and experimental validation. METHODS: We analyzed the GSE204835 transcriptomic dataset to screen differentially expressed genes (DEGs) and performed Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and Gene Set Enrichment Analysis (GSEA) for functional annotation. Immune infiltration analysis was also performed to examine the immune landscape in PIH. Least Absolute Shrinkage and Selection Operator (LASSO) regression identified key genes, which were validated in a PIH cell model. Flow cytometry and immunofluorescence assays assessed the effect of CDK7 knockdown on macrophage polarization. RESULTS: A total of 1,598 DEGs (1,123 upregulated, 475 downregulated) were identified. Enrichment analyses highlighted associations with embryonic organ development, oxidative phosphorylation, angiogenesis, and oxidative stress. Immune infiltration analysis revealed altered eosinophil and macrophage polarization in PIH. LASSO regression selected 12 key genes, with CDK7 showing the most significant upregulation in the PIH model. CDK7 knockdown promoted macrophage polarization toward the anti-inflammatory M2 phenotype. DISCUSSION: These findings link CDK7 to immune dysregulation in PIH by modulating macrophage polarization, expanding our understanding of PIH's molecular mechanisms. The study's limitations include reliance on public datasets and in vitro models, warranting in vivo validation. CONCLUSION: CDK7 emerges as a potential therapeutic target for PIH, offering new insights into immunoregulatory interventions for this complication.

Female↗
PubMed2007

Association study between the TNXB locus and schizophrenia in a Japanese population.

The chromosome 6p21-24 region, which contains the human leukocyte antigen (HLA) region, has been suggested as an important locus for a susceptibility gene for schizophrenia. Recently, a significant association between schizophrenia and the TNXB locus, located immediately telomeric of the NOTCH4 locus in the HLA region, was observed. Few studies have further investigated the region in schizophrenia. In the present study, we investigated the region in a Japanese population. Subjects included 241 patients with schizophrenia and 290 controls. Twenty-six single nucleotide polymorphisms (SNPs) and the corresponding haplotypes were analyzed. As a result, exactly the same SNPs in the TNXB locus (rs1009382 and rs204887) as in the previous study were associated with schizophrenia (P = 0.034 and 0.034, respectively, uncorrected). A SNP (rs2071287) in the NOTCH4 locus and haplotype around it were also suggested to associate with the disease, consistent with another previous study (P = 0.041 and permutation P = 0.024, respectively, uncorrected). Although these associations became insignificant after Bonferroni correction, the findings might provide support for the association of the TNXB locus or its adjacent region of the NOTCH4 locus with schizophrenia.

Adult↗
PubMed2007

Regulation of MMP-9 expression and activity in the mouse uterus by estrogen.

Matrix metalloproteinases (MMPs) are spatiotemporally expressed in the uterus across normal estrous and menstrual cycles and are known to participate in the extensive endometrial tissue remodeling. MMP-9/gelatinase B is one of the major MMPs found in the uterus that modulates uterine biology during various reproductive processes. Although it seems that uterine MMP-9 is under ovarian steroid hormonal control, there are conflicting reports regarding steroidal hormonal regulation of MMP-9 expression, and there is little information on the effects of estrogen in vivo in this respect. We therefore examined the steroidal regulation of MMP-9 within the mouse uterus. Female mice (2-3 months old) were ovariectomized and treated with estradiol-l7beta (E(2)) or E(2) + progesterone (P(4)) and uterine gelatinase activity and expression were determined. Gelatin zymography revealed that E(2) alone or in combination with P(4) increased MMP-9 activation, whereas Northern analysis showed that E(2) decreased MMP-9 steady state mRNA expression and an estrogen receptor antagonist ICI-182, 780 blocked this effect. In contrast, uterine MMP-2 expression and activity were not affected by steroidal treatments. Pretreatment with a transcription inhibitor actinomycin D or translation inhibitor cycloheximide indicates that E(2) regulates uterine MMP-9 at multiple points, involving transcriptional and posttranscriptional control as well as modulation of inhibitor activities. Collectively, these data suggest that E(2) regulates uterine MMP-9 expression and activity in vivo via a complex mechanism. This estrogen regulation of MMP-9 activity may play an important role in uterine tissue remodeling.

Animals↗
PubMed2006

Kinetic modeling and fitting software for interconnected reaction schemes: VisKin.

Reaction kinetics for complex, highly interconnected kinetic schemes are modeled using analytical solutions to a system of ordinary differential equations. The algorithm employs standard linear algebra methods that are implemented using MatLab functions in a Visual Basic interface. A graphical user interface for simple entry of reaction schemes facilitates comparison of a variety of reaction schemes. To ensure microscopic balance, graph theory algorithms are used to determine violations of thermodynamic cycle constraints. Analytical solutions based on linear differential equations result in fast comparisons of first order kinetic rates and amplitudes as a function of changing ligand concentrations. For analysis of higher order kinetics, we also implemented a solution using numerical integration. To determine rate constants from experimental data, fitting algorithms that adjust rate constants to fit the model to imported data were implemented using the Levenberg-Marquardt algorithm or using Broyden-Fletcher-Goldfarb-Shanno methods. We have included the ability to carry out global fitting of data sets obtained at varying ligand concentrations. These tools are combined in a single package, which we have dubbed VisKin, to guide and analyze kinetic experiments. The software is available online for use on PCs.

Computer Simulation↗
PubMed2006

A review and re-evaluation of an association between the NOTCH4 locus and schizophrenia.

This work reviewed all the reports on the NOTCH4 gene in schizophrenia, which have been published since the gene was found to be associated with illness among a British population in 2000. The results from independent studies were inconsistent. Allelic heterogeneity, clinical diagnosis, ethnical backgrounds, and linkage disequilibrium (LD) structures in the human genome may be major reasons for poor replication. A couple of studies suggested that the NOTCH4 gene could play a role in a subgroup of the disease, such as early-onset schizophrenia and negative symptoms. A single study revealed a weak association of the NOTCH4 gene with frontal lobe brain volumes and a strong association with frontal lobe cognitive performance. A meta-analysis showed stronger evidence of the NOTCH4 association in family-based studies than in case-control studies. In a previous study, we found that rs520692, a single nucleotide polymorphism (SNP) at the NOTCH4 locus, was associated with schizophrenia in a Chinese population. In the present study, we applied a large sample size to re-evaluate our initial findings and then confirmed the rs520692 association with illness. The pairwise measures did not show strong LD between paired SNPs although the SNPs tested are located within a 34-kb region, suggesting that LD within the NOTCH4 gene has been broken rapidly by historical recombination in the Chinese population. Taken together, the NOTCH4 gene may be associated with schizophrenia but how the gene contributes to the etiology of the illness needs a further investigation.

Asian People↗
PubMed2006

Controlled delivery of recombinant hirudin based on thermo-sensitive Pluronic F127 hydrogel for subcutaneous administration: In vitro and in vivo characterization.

Here we investigated thermo-sensitive Pluronic(R) F127 (PF127) hydrogel for the controlled release of peptide and protein drugs after subcutaneous injection, using an antithrombotic polypeptide, recombinant hirudin variant-2 (rHV2), as the model drug. The in vitro release experiment performed with a membrane-less model at 37 degrees C showed that the release of antithrombotic activity of rHV2 from PF127 gel followed zero-order kinetics and correlated well with the weight percentage of PF127 dissolved, indicating a dissolution-controlled release mechanism. The in vivo result obtained after subcutaneous injection of rHV2-loaded PF127 gel in normal rats demonstrated that PF127 gel improved the bioavailability, prolonged the antithrombotic effect of rHV2, and induced detectable plasma rHV2 concentration for a longer time in comparison with rHV2 aqueous solution. Differential scanning calorimetry, dynamic light scattering and Fourier transform infrared spectroscopy provided evidence of the interaction between PF127 and rHV2, but such interaction was unlikely to interfere the feasibility of this drug delivery system. Our current in vitro and in vivo study suggested that PF127 gel may be useful as an injectable delivery vehicle for peptides and proteins with short half-lives to prolong their therapeutic effect, increase their bioavailability and improve the clinic outcome.

Animals↗
PubMed2006

Distribution, transition, adhesion and release of insulin loaded nanoparticles in the gut of rats.

The purpose of this work was to investigate distribution, transition, bioadhesion and release behaviors of insulin loaded pH-sensitive nanoparticles in the gut of rats, as well as the effects of viscosity agent on them. Insulin was labeled with fluorescein isothiocyanate (FITC). The FITC-insulin solution and FITC-insulin nanoparticle aqueous dispersions with or without hydropropylmethylcellulose (HPMC, 0.2%, 0.4%, or 0.8% (w/v)) were orally administered to rats, respectively. The amounts of FITC-insulin in both the lumen content and the intestinal mucosa were quantified by a spectrofluorimeter. The release profiles in the gut were plotted by the percentages of FITC-insulin released versus time. FITC-insulin nanoparticle aqueous dispersion showed similar stomach but lower intestine empty rates, and enhanced intestinal mucosa adhesion in comparison with FITC-insulin solution. Addition of the HPMC reduced the stomach and intestine empty rates, enhanced the adhesion of FITC-insulin to the intestine mucosa. The release of FITC-insulin from nanoparticles in the gut showed an S-shape profile, and addition of HPMC prolonged the release half-life from 0.77 to 1.51h. It was concluded that the behaviors of pH-sensitive nanoparticles tested in gastrointestinal tract of rats and the addition of HPMC were favorable to the absorption of the drug loaded.

Animals↗
PubMed2006

Cell-ELISA detection of antineuronal antibodies in central nervous system involvement in systemic lupus erythematosus.

OBJECTIVE: To develop a cell-ELISA method to detect antineuronal antibodies (anti-Ns) and evaluate the diagnostic value of anti-Ns in central nervous system involvement in systemic lupus erythematosus (CNS-SLE). METHOD: Anti-N was assessed in both serum and cerebrospinal fluid (CSF) samples from 38 patients with CNS-SLE, 29 with SLE without CNS involvement (non-CNS-SLE), 36 with other rheumatic diseases and 59 with non-rheumatic diseases with the CNS manifestations using a cell-ELISA method with 1% paraformaldehyde-fixed SK-N-MC neuroblastoma cells as substrate. Serum samples from 37 healthy donors were also included in this study. Patients with CNS-SLE who were anti-N positive in CSF were studied serially for CSF anti-N levels at times of treatment-associated improvement in CNS symptoms. RESULTS: Serum anti-N levels were significantly increased in patients with SLE compared with other groups, with a sensitivity of 61.2% (41/67) and a specificity of 91.8% (p<0.001). CSF anti-N levels were significantly increased in patients with CNS-SLE, with a sensitivity of 47.4% (18/38) and a specificity of 89.7%, whereas only 10.3% (3/29) of patients with non-CNS-SLE had increased anti-N in CSF (p<0.001). CSF anti-N levels decreased significantly after effective treatment of CNS-SLE (p<0.05). CONCLUSION: Serum anti-N is relatively specific to SLE. CSF anti-N is a sensitive and relatively specific antibody in diagnosing CNS-SLE and correlates with CNS-SLE activity.

Adolescent↗
PubMed2006

Association study of the dysbindin (DTNBP1) gene in schizophrenia from the Japanese population.

Dysbindin (DTNBP1: dystrobrevin binding protein 1), located on 6p22.3, is a candidate susceptibility gene for schizophrenia. Several studies, mostly in Caucasians, have provided evidence for an association between schizophrenia and the gene, although no common polymorphism or haploytpe has been established. In Asian populations, two studies investigated a limited number of single nucleotide polymorphisms (SNPs) of dysbindin and observed support for the association. In the present study, we investigated 12 SNPs of dysbindin, including those examined in previous Asian studies, and the corresponding haplotypes in a Japanese people with schizophrenia. As a result, no significant difference was observed between patients and controls in allelic frequencies or genotypic distributions of the 12 SNPs. Permutation test however showed significant differences in frequencies of the estimated 10-marker haplotypes between patients and controls (global p = 0.006). The present study may provide further support for an association between dysbindin and schizophrenia in Asian populations. The results might be similar to a previous Asian study, but specific haplotypes suggested for the association differed between the studies. Studies with more markers and subjects may be required before firm conclusions can be reached.

Adult↗
PubMed2006

The effects of protein phosphatase inhibitors on the duration of central sensitization of rat dorsal horn neurons following injection of capsaicin.

Protein kinases and phosphatases catalyze opposing reactions of phosphorylation and dephosphorylation, which may modulate the function of crucial signaling proteins in central nervous system. This is an important mechanism in the regulation of intracellular signal transduction pathways in nociceptive neurons. To explore the role of protein phosphatase in central sensitization of spinal nociceptive neurons following peripheral noxious stimulation, using electrophysiological recording techniques, we investigated the role of two inhibitors of protein phosphatase type 2A (PP2A), fostriecin and okadaic acid (OA), on the responses of dorsal horn neurons to mechanical stimuli in anesthetized rats following intradermal injection of capsaicin. Central sensitization was initiated by injection of capsaicin into the plantar surface of the left paw. A microdialysis fiber was implanted in the spinal cord dorsal horn for perfusion of ACSF and inhibitors of PP2A, fostriecin and okadaic acid. We found that in ACSF pretreated animals, the responses to innocuous and noxious stimuli following capsaicin injection increased over a period of 15 min after injection and had mostly recovered by 60 min later. However, pre- or post-treatment with the phosphatase inhibitors, fostriecin or OA, significantly enhanced the effects of capsaicin injection by prolonging the responses to more than 3 hours. These results confirm that blockade of protein phosphatase activity may potentiate central sensitization of nociceptive transmission in the spinal cord following capsaicin injection and indicate that protein phosphatase type 2A may be involved in determining the duration of capsaicin-induced central sensitization.

Afferent Pathways↗
PubMed2006

[Risk factor assessment of cardiocerebrovascular diseases in patients with rheumatoid arthritis].

OBJECTIVE: To assess the prevalence of cardiocerebrovascular diseases (CCVDs) in the patients with rheumatoid arthritis (RA) and analyzed the risk factors. METHODS: The clinical data of 568 RA patients hospitalized 1995 - 2005, were analyzed retrospectively. RESULTS: (1) The total prevalence of CCVD was 16.2% (92/568). The prevalence rate of coronary heart disease, cerebrovascular disease, hypertensive heart disease together with coronary heart disease including 2 cases of heart failure, atherogenesis in large and medium-size arteries proved by color Doppler ultrasonic examination, and gangrene of extremities were 53.26% (49/92), 22.83% (21/92), 13.04% (12/92), 6.52% (6/92), and 4.34% (4/92) respectively. (2) Complication of CCVD in RA patients was associated with age, DAS28 disease activity score, number of involved extra-articular organs, platelet count, hyperfibrinogenemia, and C-reactive protein; and was not associated with sex, auto-antibody, hereditary factor, other traditional CCBVD risk factors, and the number of risk factors. (3) The occurrence of CCVD in RA patients was significantly correlated with poor therapeutic response, lack of persistent effective prevention of the traditional risk factors, use of cyclooxygenase (Cox)-2 specific inhibitors, and long-term medication of high-dosage glucocorticoid. CONCLUSION: Activity of the disease of RA, high inflammatory index, extra-articular involvement, poor response to treatment, lack of persistent effective prevention of the traditional risk factors, use of Cox-2 specific inhibitor, and long-term medication of high-dosage glucocorticoid are risk factors of CCVD-co-morbidities in RA pate.

Aged↗
PubMed2006

Molecular cloning and characterization of a novel V-ATPase associated protein, DVA9.2, from human dendritic cells.

The vacuolar proton-ATPase (V-ATPase) is a ubiquitous ATP-driven H(+) transporter that functions in numerous cell processes. Accumulating evidence shows important roles of V-ATPase in tumor metastasis and antigen presentation of dendritic cells (DC). A novel V-ATPase associated protein, designated as DVA9.2 (dendritic cell-derived V-ATPase associated protein of 9.2 kDa), has been identified from a human DC cDNA library by large-scale random sequencing. Full length cDNA of DVA9.2 encodes an 81-residue protein that shares 70-80% homology with human V-ATPase subunit M9.2. Distant relationship is also found with Vma21p, a yeast protein required for V-ATPase assembly. DVA9.2 contains a conserved domain, ATP synthase subunit H (pafm05493), and two membrane-spanning helices. DVA9.2 mRNA is detectable in several human tumor cell lines as well as some human normal cells and tissues. Moreover, the inducible expression of DVA9.2 mRNA in DC during maturation is observed. DVA9.2 displays integration with membrane and main localization in lysosome, endoplasmic reticulum and Golgi-associated organelles, only less at the plasma membrane. In addition, DVA9.2 is co-localized with V(0)-sector subunit a. Silencing of DVA9.2 by small interfering RNA (siRNA) does not affect the V-ATPase activity in cell membrane fractions or attenuate the migration and invasion in breast cancer MDA-MB-231 cells. These results indicate that DVA9.2, as a novel V-ATPase-associated protein, is not essential for the activity of V-ATPase complex and may be involved in functions of DC.

Animals↗
PubMed2006

Microregion detection of ionic liquid microemulsions.

Nonaqueous ionic liquid (IL) microemulsion consisting of IL, 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF(4)), surfactant TX-100, and toluene was prepared and the phase behavior of the ternary system was investigated. Electrical conductivity measurement was used for investigating the microregions of the nonaqueous IL microemulsions. On the basis of the percolation theory, the bmimBF(4)-in-toluene (IL/O), bicontinuous, and toluene-in-bmimBF(4) (O/IL) microregions of the microemulsions were successfully identified using insulative toluene as the titration phase. However, this method was invalid when conductive bmimBF(4) acted as the titration phase. The microregions obtained by conductivity measurements were further proved by electrochemical cyclic voltammetry experiments. The results indicated that the conductivity method was feasible for identifying microstructures of the nonaqueous IL microemulsions.

Journal Article↗
PubMed2006

Long-term studies on the stability and oral bioavailability of cyclosporine A nanoparticle colloid.

The present study was geared at the long-term stability and the changes in oral bioavailability of CyA Eudragit S100 nanoparticles stabilized by suspending agents. CyA Eudragit S100 nanoparticle colloids were prepared by quasi-emulsion solvent diffusion technique and they were mixed with Xanthan gum to obtain suspended nanoparticle colloids. The suspended nanoparticle colloids were preserved at different temperatures for different period of time, as long as 18 months. During the storage period, the CyA concentration, particle size, pH and viscosity were determined. The results indicated that CyA concentration, particle size and viscosity of the colloids had no obvious change. However, the pH increased slightly from 5.5 to about 6.4. The results of bioavailability and pharmacokinetic study revealed that all formulations of nanoparticles showed higher C(max) and higher AUC(0-24) values than that of reference (Neoral). The relative bioavailability of S-CyA-S100 NP initial compared with Neoral was 162.8%. The C(max) and AUC(0-24) values of nanoparticle formulations at 12 and 18 months were both lower than that of the initial. The bioequivalency was suggested between the tested nanoparticle formulations at the initial and 12 months. It was deduced by surface analysis, TEM observation, in vitro release as well as the characteristics of Eudragit S100 that the decrease in bioavailability might be due to the pH change of the nanoparticle colloid.

Administration, Oral↗
PubMed2006

Protein phosphatase 2A regulates central sensitization in the spinal cord of rats following intradermal injection of capsaicin.

BACKGROUND: Intradermal injection of capsaicin into the hind paw of rats induces spinal cord central sensititzation, a process in which the responsiveness of central nociceptive neurons is amplified. In central sensitization, many signal transduction pathways composed of several cascades of intracellular enzymes are involved. As the phosphorylation state of neuronal proteins is strictly controlled and balanced by the opposing activities of protein kinases and phosphatases, the involvement of phosphatases in these events needs to be investigated. This study is designed to determine the influence of serine/threonine protein phosphatase type 2A (PP2A) on the central nociceptive amplification process, which is induced by intradermal injection of capsaicin in rats. RESULTS: In experiment 1, the expression of PP2A protein in rat spinal cord at different time points following capsaicin or vehicle injection was examined using the Western blot method. In experiment 2, an inhibitor of PP2A (okadaic acid, 20 nM or fostriecin, 30 nM) was injected into the subarachnoid space of the spinal cord, and the spontaneous exploratory activity of the rats before and after capsaicin injection was recorded with an automated photobeam activity system. The results showed that PP2A protein expression in the spinal cord was significantly upregulated following intradermal injection of capsaicin in rats. Capsaicin injection caused a significant decrease in exploratory activity of the rats. Thirty minutes after the injection, this decrease in activity had partly recovered. Infusion of a phosphatase inhibitor into the spinal cord intrathecal space enhanced the central sensitization induced by capsaicin by making the decrease in movement last longer. CONCLUSION: These findings indicate that PP2A plays an important role in the cellular mechanisms of spinal cord central sensitization induced by intradermal injection of capsaicin in rats, which may have implications in clinical pain therapy.

Animals↗