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1.
Eur J Nutr ; 60(5): 2781-2793, 2021 Aug.
Article En | MEDLINE | ID: mdl-33416981

PURPOSE: 6-Shogaol, an active phenolic compound from ginger (Zingiber officinale), can inhibit the growth of a variety of human cancer cells. Nevertheless, its underlying molecular mechanisms in cervical cancer remain unclear. In this study, we systematically examine the inhibitory effect of 6-shogaol on cervical cancer in vitro and in vivo. METHODS: Cell proliferation was assessed by CCK8 assay and colony formation assay in HeLa and SiHa cells. We analyzed cell cycle and apoptosis through flow cytometry. GFP-LC3 puncta and transmission electron microscopy were used to observe autophagic bodies. Wound-healing assay and transwell assay were used for evaluating the migration of cells. Western blot was applied to detect protein expression levels. RESULTS: 6-Shogaol could suppress cell proliferation and migration, cause cell cycle arrest in the G2/M phase in HeLa and SiHa cells. Moreover, 6-shogaol triggered the apoptosis process through the mitochondrial pathway by downregulating the expression levels of p-PI3K, p-Akt and p-mTOR. Further research indicated that the induction of apoptosis by 6-shogaol was remarkably decreased after the treatment of ROS scavenger and PI3K agonist. Additionally, 6-shogaol increased the number of LC3-positive puncta and autophagic bodies per cell in both HeLa and SiHa cells. Pretreatment of cells with Bafilomycin A1, an autophagy inhibitor, accelerated 6-shogaol mediated cell apoptosis, suggesting that induction of autophagy by 6-shogaol is suppressive to apoptosis. Furthermore, in vivo data revealed that 6-shogaol significantly inhibited tumor growth and cell proliferation in tumor tissues. CONCLUSION: These findings suggested that 6-shogaol could be developed as a functional food ingredient, which is potentially used as therapeutic agents for patients with cervical cancer.


Uterine Cervical Neoplasms , Zingiber officinale , Apoptosis , Autophagy , Catechols , Cell Line, Tumor , Cell Proliferation , Female , Humans , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , Uterine Cervical Neoplasms/drug therapy
2.
Math Biosci Eng ; 16(6): 6794-6804, 2019 07 26.
Article En | MEDLINE | ID: mdl-31698588

PURPOSE: Inflammatory myofibroblastic tumors (IMT) was a rare kind of tumor defined by WHO since 2012. Little was known about this disease. There were controversies about IMT's behavior, predilection site, age distribution, and the best treatment methods. Here we provided a systematic overview on tumor demographical, clinical, biological features as well as treatment efficacy based on real cases from Surveillance, Epidemiology, and End Results (SEER) database. METHODS: 92 patients diagnosed with IMT by histopathology were drawn from SEER database between 2002 and 2014. Patient demographics, clinical features and treatment information were analyzed. RESULTS: The mean age of onset was 47.4 ± 22.4 years (0 to 83y) and the ages prone to this disease are middle-aged (from 41y to 64y), accounting for 1/3 of all patients. Three peak ages of onsets were 0-4y, 36-40y and more than 50y. 42% of the tumors were located in the soft tissues of limbs, hip, shoulder, head, face and neck. The average tumor sizes were 6.5 ± 5.3cm (1cm to 25cm). Survival in the group of tumor size smaller than 6.5cm was better compared to group of tumor size larger than 6.5cm (P < 0.05). Most of the tumors were malignant or malignant potential (89%), though local and distant metastasis rate were low (5%). Surgery was the most common treatment. However, the survival benefit was still uncertain compared to adjuvant chemotherapy or radiotherapy. Multivariate regression analysis demonstrated that young patients had better survival than old ones. CONCLUSIONS: IMT was a malignant tumor with low risk of local and distant metastasis. The peak ages were 0-4y, 36-40y and more than 50y. The prone sites were the soft tissues of the limbs, hip, shoulder, head, face and neck. Tumor sizes and ages were the factors correlated with survival time.


Neoplasms, Muscle Tissue/epidemiology , Neoplasms, Muscle Tissue/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Multivariate Analysis , Neoplasm Metastasis , Neoplasms, Muscle Tissue/therapy , Proportional Hazards Models , SEER Program , Treatment Outcome , United States , Young Adult
3.
Environ Sci Process Impacts ; 19(10): 1346-1354, 2017 Oct 18.
Article En | MEDLINE | ID: mdl-28892110

The concentrations and spatial distributions of hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) were measured in tree bark from different functional areas of Shanghai. ΣHBCDD (sum of α-, ß-, and γ-HBCDD) concentrations ranged from 1.2 × 102 to 6.6 × 103 ng g-1 lw (median 5.7 × 102 ng g-1 lw) and TBBPA concentrations ranged from 48 to 7.2 × 104 ng g-1 lw (median 2.8 × 102 ng g-1 lw). The concentrations of ΣHBCDD and TBBPA all followed the order of industrial areas > commercial areas > residential areas. The mean percentage of α-HBCDD in bark samples (44%) from Shanghai was higher than that in technical HBCDD products, but comparable with that in air. The concentrations of TBBPA and individual HBCDD diastereoisomers between industrial areas and commercial areas were correlated. Based on the concentrations of HBCDD in the bark, the corresponding atmospheric HBCDD concentrations were estimated. Compared with the published data for HBCDD in urban air, the estimated atmospheric HBCDD concentrations in Shanghai had a relatively high level, and more attention should be paid to the pollution status of HBCDD in Shanghai.


Environmental Monitoring/methods , Environmental Pollutants/analysis , Flame Retardants/analysis , Hydrocarbons, Brominated/analysis , Plant Bark/chemistry , Polybrominated Biphenyls/analysis , China , Cities , Industry
4.
Ecotoxicol Environ Saf ; 145: 659-664, 2017 Nov.
Article En | MEDLINE | ID: mdl-28823766

Perfluorinated compounds (PFCs) have received increasing attention worldwide recently because of potential risk to aquatic environment and living organisms. Herein, occurrence and spatial distributions of 17 selected PFCs were investigated in surface water adjacent to potential industrial emission categories in Shanghai. The results showed the distributions of PFCs in the ambient rivers were greatly affected by those industrial sources. Perfluorooctanoic acid (PFOA) and other short-chain PFCs such as perfluoropentanoic acid (PFPeA) and perfluorooctanesulfonate (PFBS) were detected as the predominant species in all samples. Specifically, the total concentrations of PFCs (∑PFCs) near the airport ranged from 142 to 264ngL-1, with PFOA, PFPeA, and PFBS as most prevalent. While near the fluorochemical plant and metal plating, concentrations of ∑PFCs ranged from 200 to 2143ngL-1 and 211ngL-1 to 705ngL-1; and PFOA was the predominant individual PFCs, with the highest concentration of 1985ngL-1. However, concentrations of PFOS were found at relatively low level, which ranged from < 0.06 to 4.44ngL-1. The Spearman correlation analysis of concentration of individual PFCs showed that PFOA and perfluorohexanoic acid (PFHxA) was positive, while the correlation between PFOA and perfluorohexansulfonate (PFHxS) was negative near the airport, indicating PFOA and PFHxA may share common sources. Preliminary ecological risk evaluation of PFCs in adjacent water of the industrial emission areas suggested these emission categories posed higher risks than other area, although the risk level was still relatively safe.


Air Pollution , Environmental Monitoring/methods , Fluorocarbons/analysis , Industry , Rivers/chemistry , Water Pollutants, Chemical/analysis , Air Pollution/analysis , China , Risk Assessment , Water Supply
5.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 37(4): 414-418, 2017 04.
Article Zh | MEDLINE | ID: mdl-30650496

Objective To study the Chinese Medical (CM) syndrome distribution in patients with colorectal cancer in adjuvant chemotherpay period. Methods Totally 160 patients with colorectal cancer were recruited and clinical data for the CM syndromes before receiving adjuvant chemotherapy, in the early, mid and after period of adjuvant chemotherapy were collected. The distribution and dynamic chan- ges of CM syndromes were observed. Results The primary CM syndrome before chemotherapy were yin deficiency induced inner heat with dampness (40 cases, 40. 0%) and qi deficiency syndrome(30 ca- ses,30. 0%) concluded by 14 symptoms during cluster analyses among 100 cases.The primary CM syn- drome at the early period of adjuvant chemotherapy was Pi and blood deficiency syndrome (60 cases, 50.0%) , closely followed by syndrome of yin deficiency induced inner heat (45 cases, 37.5%) by 16 symptoms during cluster analyses among 120 cases. The CM syndrome at the mid period of adjuvant chemotherapy consisted of syndrome of Gan-heat and Pi-deficiency(51 cases ,44. 7%), syndrome of qi and blood deficiency (40 cases,35. 1%) , as well as Pi-deficiency with dampness syndrome (19 cases, 16.7%) by 22 symptoms during cluster analyses among 114 cases; at the period after adjuvant chemo- therapy, the major CM syndromes was deficiency syndrome, including qi and blood deficiency syndrome (32 cases,29. 1%), Pi-deficiency syndrome(29 cases,26. 4%) and Gan-Shen yin deficiency syndrome (49 cases,44. 6%) by 24 symptoms during cluster analyses among 110 cases. Conclusion During the period of adjuvant chemotherapy in colorectal cancer patients, the mainly CM syndromes shows the defi- ciency syndrome.


Colorectal Neoplasms , Medicine, Chinese Traditional , Yang Deficiency , Yin Deficiency , Chemotherapy, Adjuvant , Colorectal Neoplasms/complications , Colorectal Neoplasms/drug therapy , Humans , Syndrome
6.
J Theor Biol ; 380: 53-9, 2015 Sep 07.
Article En | MEDLINE | ID: mdl-25997794

The stochastic Eigen model proposed by Feng et al. (2007) (Journal of Theoretical Biology, 246, 28) showed that error threshold is no longer a phase transition point but a crossover region whose width depends on the strength of the random fluctuation in an environment. The underlying cause of this phenomenon has not yet been well examined. In this article, we adopt a single peak Gaussian distributed fitness landscape instead of a constant one to investigate and analyze the change of the error threshold and the statistical property of the quasi-species population. We find a roughly linear relation between the width of the error threshold and the fitness fluctuation strength. For a given quasi-species, the fluctuation of the relative concentration has a minimum with a normal distribution of the relative concentration at the maximum of the averaged relative concentration, it has however a largest value with a bimodal distribution of the relative concentration near the error threshold. The above results deepen our understanding of the quasispecies and error threshold and are heuristic for exploring practicable antiviral strategies.


Models, Statistical
7.
Mol Med Rep ; 9(2): 401-6, 2014 Feb.
Article En | MEDLINE | ID: mdl-24276408

ω-3 polyunsaturated fatty acids (n-3 PUFA), in particular the marine-derived forms eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been demonstrated to affect cancer cell replication, the cell cycle and cell death. Epidemiological studies have also suggested diets rich in n-3 PUFA were inversely correlated with the development of cancer. In the present study, we explored the effects of DHA and EPA on the proliferation activity and apoptosis of the human lung adenocarcinoma cell line A549. A methyl thiazolyl tetrazolium (MTT) assay was used to detect cell proliferation, apoptosis was detected by flow cytometry and morphological analysis was determined by fluorescence microscopy and transmission electron microscopy. A549 cells were treated with different doses of DHA (40, 45, 50 and 55 µg/ml) or EPA (45, 50, 55 and 60 µg/ml) for 24, 48 and 72 h. The results demonstrated that DHA and EPA significantly suppressed the proliferation of A549 cells and induced apoptosis of A549 cells in a dose- and time-dependent manner. The apoptotic phenomenon was also confirmed by fluorescence microscopy and transmission electron microscopy. Furthermore, compared with the control, the formation of autophagosomes was clearly enhanced in DHA­ or EPA-treated cells. In conclusion, DHA and EPA inhibited the proliferation of A549 cells and induced cell apoptosis and autophagy, which may provide new safe and effective options for the treatment of lung cancer in the future.


Adenocarcinoma/drug therapy , Cell Proliferation/drug effects , Fatty Acids, Omega-3/administration & dosage , Lung Neoplasms/drug therapy , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Adenocarcinoma of Lung , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Docosahexaenoic Acids/administration & dosage , Eicosapentaenoic Acid/administration & dosage , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology
8.
Gastroenterol Res Pract ; 2012: 752940, 2012.
Article En | MEDLINE | ID: mdl-22888341

Objective. The present study was performed to investigate the effect of N-desulfated heparin on basic fibroblast growth factor (bFGF) expression, tumor angiogenesis and metastasis of gastric carcinoma. Methods. Human gastric cancer SGC-7901 tissues were orthotopically implanted into the stomach of NOD SCID mice. Twenty mice were randomly divided into two groups which received either intravenous injection of 0.9% NaCl solution (normal saline group) or 10 mg/kg N-desulfated heparin (N-desulfated heparin group) twice weekly for three weeks. In vitro, human gastric carcinoma SGC-7901 cells were treated with N-desulfated heparin in different concentration (0.1 mg/mL, 1 mg/mL, N-desulfated heparin group), and treated with medium (control group). Results. In vivo, the tumor metastasis rates were 9/10 in normal saline group and 2/10 in N-desulfated heparin group (P < 0.05). The intratumoral microvessel density was higher in normal saline group than in N-desulfated heparin group (P < 0.05). bFGF expression in gastric tissue was inhibited by N-desulfated heparin (P < 0.05). There was no bleeding in N-desulfated heparin group. In vitro, N-desulfated heparin inhibited significantly bFGF protein and mRNA expression of gastric carcinoma cells (P < 0.05). Conclusions. N-desulfated heparin can inhibit the metastasis of gastric cancer through inhibiting tumor bFGF expression and tumor angiogenesis with no obvious anticoagulant activity.

9.
World J Gastroenterol ; 17(6): 727-34, 2011 Feb 14.
Article En | MEDLINE | ID: mdl-21390142

AIM: To gain new insights into tumor metabolism and to identify possible biomarkers with potential diagnostic values to predict tumor metastasis. METHODS: Human gastric cancer SGC-7901 cells were implanted into 24 severe combined immune deficiency (SCID) mice, which were randomly divided into metastasis group (n = 8), non-metastasis group (n = 8), and normal group (n = 8). Urinary metabolomic information was obtained by gas chromatography/mass spectrometry (GC/MS). RESULTS: There were significant metabolic differences among the three groups (t test, P < 0.05). Ten selected metabolites were different between normal and cancer groups (non-metastasis and metastasis groups), and seven metabolites were also different between non-metastasis and metastasis groups. Two diagnostic models for gastric cancer and metastasis were constructed respectively by the principal component analysis (PCA). These PCA models were confirmed by corresponding receiver operating characteristic analysis (area under the curve = 1.00). CONCLUSION: The urinary metabolomic profile is different, and the selected metabolites might be instructive to clinical diagnosis or screening metastasis for gastric cancer.


Biomarkers, Tumor/urine , Gas Chromatography-Mass Spectrometry/methods , Metabolomics/methods , Neoplasm Metastasis , Stomach Neoplasms/pathology , Stomach Neoplasms/urine , Animals , Cell Line, Tumor , Humans , Male , Mice , Mice, SCID , Neoplasm Transplantation , Principal Component Analysis , ROC Curve , Random Allocation
10.
World J Gastroenterol ; 16(46): 5874-80, 2010 Dec 14.
Article En | MEDLINE | ID: mdl-21155010

AIM: To elucidate the underlying mechanisms of metastasis and to identify the metabolomic markers of gastric cancer metastasis. METHODS: Gastric tumors from metastatic and non-metastatic groups were used in this study. Metabolites and different metabolic patterns were analyzed by gas chromatography, mass spectrometry and principal components analysis (PCA), respectively. Differentiation performance was validated by the area under the curve (AUC) of receiver operating characteristic curves. RESULTS: Twenty-nine metabolites were differentially expressed in animal models of human gastric cancer. Of the 29 metabolites, 20 were up-regulated and 9 were down-regulated in metastasis group compared to non-metastasis group. PCA models from the metabolite profiles could differentiate the metastatic from the non-metastatic specimens with an AUC value of 1.0. These metabolites were mainly involved in several metabolic pathways, including glycolysis (lactic acid, alaline), serine metabolism (serine, phosphoserine), proline metabolism (proline), glutamic acid metabolism, tricarboxylic acid cycle (succinate, malic acid), nucleotide metabolism (pyrimidine), fatty acid metabolism (docosanoic acid, and octadecanoic acid), and methylation(glycine). The serine and proline metabolisms were highlighted during the progression of metastasis. CONCLUSION: Proline and serine metabolisms play an important role in metastasis. The metabolic profiling of tumor tissue can provide new biomarkers for the treatment of gastric cancer metastasis.


Chromatography, Gas/methods , Mass Spectrometry/methods , Metabolomics , Neoplasm Metastasis , Stomach Neoplasms , Animals , Biomarkers, Tumor/metabolism , Humans , Male , Mice , Mice, SCID , Random Allocation , Stomach Neoplasms/chemistry , Stomach Neoplasms/metabolism , Stomach Neoplasms/pathology
11.
Zhonghua Zhong Liu Za Zhi ; 32(2): 84-7, 2010 Feb.
Article Zh | MEDLINE | ID: mdl-20403235

OBJECTIVE: To establish a human gallbladder carcinoma cell line derived from a metastatic gallbladder carcinoma and identify its biological characteristics. METHODS: Tissue samples were separated from the surgical specimen obtained from a patient with metastatic carcinoma and single-cell suspension was prepared. Then the cells were cultured in DMEM medium supplemented with 15% fetal bovine serum. The morphology of tumor cells was observed under an electron microscope. The cell growth curve was plotted. The tumorigenicity of the cell line was studied by subcutaneous inoculation in SCID mice. The cells were infected by lentiviral vector carrying fluorescent report genes (lenti-GFP and lenti-Red2) separately for expressions of GFP and Red2, respectively. RESULTS: A novel metastatic gallbladder carcinoma cell line was successfully established and named "EH-GB1". It could be passaged for over 20 generations with typical malignant epithelial morphology and a stable growth cycle of 24 h. Tumors were formed in all of the 10 SCID mice inoculated with EH-GB1 cells subcutaneously, and the tumor cells were tumor marker CA19-9-positive. Continuous expressions of fluorescent report genes were observed in EH-GB1 cells infected by lenti-GFP and lenti-Red2. CONCLUSION: EH-GB1 cells might be the first stable cell line of human gallbladder carcinoma established from a metastatic focus of gallbladder carcinoma. This cell line with continuous expressions of GFP and Red2 might be a novel and perfect experimental model for clinical and basic research on gallbladder carcinoma.


Abdominal Neoplasms/secondary , Adenocarcinoma/pathology , Cell Line, Tumor/pathology , Gallbladder Neoplasms/pathology , Abdominal Neoplasms/metabolism , Abdominal Neoplasms/pathology , Abdominal Wall , Adenocarcinoma/metabolism , Adenocarcinoma/secondary , Animals , CA-19-9 Antigen/metabolism , Cell Line, Tumor/metabolism , Female , Gallbladder Neoplasms/metabolism , Genes, Reporter , Green Fluorescent Proteins/metabolism , Humans , Mice , Mice, Nude , Mice, SCID , Middle Aged , Neoplasm Transplantation
12.
Hepatol Res ; 40(2): 216-28, 2010 Feb.
Article En | MEDLINE | ID: mdl-19788685

AIM: Gene therapy represents a promising therapeutic strategy for hepatocellular carcinoma (HCC). To improve the ratio of killing efficacy on tumor cells to side-effect on normal cells, we constructed an oncolytic adenovirus vector, AdSu-hE, expressing the human endostatin (hE) gene, in which the chimeric promoter of human epidermal growth factor receptor 2 enhancer and human telomerase reverse transcriptase promoter was used to control the adenoviral E1a gene. METHODS: Tumor-selective replication of adenovirus AdSu-hE and its concomitant expression of endostatin were measured by 50% tissue culture infective dose method, fluorescent protein expression, Western blot and enzyme linked immunosorbent assay in cancer and normal cell lines. The antitumor efficacy was observed in nude mice bearing human HCCs. RESULTS: The oncolytic adenovirus AdSu-hE replicated restrictedly in telomerase-positive cancer cells and resulted in oncolysis, but did not replicate in normal cell lines. Along with virus replication, AdSu-hE mediated 5-fold increased expression of endostatin in tumor cells compared with that in normal cells. Moreover, AdSu-hE expressed more endostatin in cancer cells than the non-replicative adenovirus vector Ad-hE. In vivo administration of the oncolytic adenovirus AdSu-hE into HCC-bearing nude mice produced a significant tumor reduction by synergistic effects of virus oncolysis and endostatin antiangiogenesis. CONCLUSION: The oncolytic virus with antiangiogenesis gene driven by the chimeric promoter has an improved killing efficacy on tumor cells, and may be useful for cancer gene therapy.

13.
Hypertens Res ; 31(4): 805-16, 2008 Apr.
Article En | MEDLINE | ID: mdl-18633193

The objective of this study was to examine the effects of moderate and high levels of exercise volume on endothelium-dependent vasodilation and associated changes in vascular endothelial/inducible nitric oxide synthase (eNOS and iNOS) and heme oxygenase (HO). Male Sprague-Dawley rats were assigned to sedentary control, acute (2 weeks), or chronic (6 weeks) treadmill running at moderate intensity (50% maximal aerobic velocity) with different durations of exercise episodes: 2 h/d (endurance training, moderate volume) and 3 h/d (intense training, high volume). Endothelium-dependent vascular function was examined in isolated thoracic aorta. Co-localization and contents of aortic eNOS/iNOS and HO-1/HO-2 were determined with immunofluorescence and Western blotting. Compared with sedentary controls, rats subjected to acute and chronic endurance training showed enhanced endothelium-dependent relaxation (p<0.01). Whereas acetylcholine-induced dilation was inhibited completely by NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) in sedentary controls, the dilation in the training groups was only partly blocked by L-NAME (inhibition was 98+/-3%, 79+/-6%, and 77+/-5% in sedentary control, acute, and chronic training groups, respectively, p<0.01). The remnant dilation in the training groups was further inhibited by HO inhibitor protoporphyrin IX zinc, with concomitant elevation in aortic eNOS as well as HO-1 and HO-2. In contrast to endurance exercise, high-volume intense training resulted in mild hypertension with significant impairment in endothelium-dependent vasodilation and profuse increases in aortic iNOS and eNOS (p<0.01). In conclusion, endothelium-dependent vasodilation is improved by endurance exercise but impaired by chronic intense training. Elevations of vascular eNOS and HO-1/HO-2 may contribute to enhanced vasodilation, which can be offset by intense training and elevation in vascular iNOS.


Heme Oxygenase (Decyclizing)/metabolism , Nitric Oxide Synthase Type II/metabolism , Physical Conditioning, Animal/physiology , Physical Exertion/physiology , Vasodilation/physiology , Animals , Aorta/enzymology , Endothelium, Vascular/enzymology , Immunohistochemistry , Male , Nitrates/blood , Nitric Oxide Synthase Type III , Nitrites/blood , Rats , Rats, Sprague-Dawley
14.
Lab Anim (NY) ; 35(8): 37-41, 2006 Sep.
Article En | MEDLINE | ID: mdl-16943792

Several research groups are using the Yangtze field vole as a model for studying schistosome infection, but relatively little is known about the species's reproductive physiology. The authors examined the vole's in vivo and in vitro embryonic development as well as the efficacy of in vitro fertilization using either fresh or cryopreserved sperm to breed these rodents.


Arvicolinae/physiology , Cryopreservation/veterinary , Embryonic Development/physiology , Fertilization in Vitro/veterinary , Semen Preservation/veterinary , Animals , Arvicolinae/embryology , Cryopreservation/methods , Female , Fertilization in Vitro/standards , Male , Ovulation Induction/methods , Ovulation Induction/veterinary , Pregnancy , Semen Preservation/methods
15.
Clin Exp Pharmacol Physiol ; 33(10): 910-6, 2006 Oct.
Article En | MEDLINE | ID: mdl-17002667

There is considerable controversy regarding the tolerance of diabetic hearts to ischaemia and the underlying mechanisms responsible for the increased heart tolerance to ischamia remain uncertain. In the present study, we observed, in vitro, type 1 diabetic heart responses to ischaemia and reperfusion at different degrees of hyperglycaemia. In addition, the possible role of increased osmolarity in cardioprotection due to hyperglycaemia was evaluated. Hearts from 3 week streptozocin-induced diabetic rats were isolated and perfused in a Langendorff apparatus and subjected to 30 min ischaemia and 30 min reperfusion. Cardiac function and the electrocardiogram were recorded. Myocardial content of osmolarity associated heat shock protein (hsp) 90, heme oxygenase (HO)-1 and anti-oxidant enzymes were determined in diabetic or hyperosmotic solution-perfused hearts using western blot. The hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG; 2 x 10(-7) mol/L) or the nitric oxide synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (1 x 10(-5) mol/L) was added to the perfusate to observe the effects of hsp90 inhibition and hsp90-associated endothelial NOS on ischaemic responses of diabetic hearts. Compared with normal control rats, diabetic hearts with severe hyperglycaemia (blood glucose > 20 mmol/L) showed markedly improved postischaemic heart function with fewer reperfusion arrhythmias. Mild hyperglycaemia (< 12 mmol/L) exhibited no significant cardioprotection. Elevated expression of hsp90 accompanied the enhanced resistance to ischaemia in diabetic hearts, which was abrogated by 17-AAG. In the presence of the NOS inhibitor, heart function was preserved, whereas reperfusion arrhythmias were increased in diabetes. Diabetic hearts also had markedly elevated HO-1 and catalase, with no significant change in superoxide dismutase. Hyperosmotic perfusion with glucose or mannitol also increased myocardial hsp90 and catalase. The present findings reveal that heart resistance to ischaemia is increased in short-term type 1 diabetes with severe hyperglycaemia. Elevated osmolarity caused by significant hyperglycaemia may contribute to the enhanced myocardial activity against oxidative injury during ischaemia and reperfusion.


Diabetes Mellitus, Type 1/pathology , Myocardial Ischemia/pathology , Osmolar Concentration , Animals , Blood Glucose , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 1/chemically induced , HSP90 Heat-Shock Proteins/metabolism , Hyperglycemia/pathology , In Vitro Techniques , Ischemic Preconditioning, Myocardial/methods , Male , Myocardial Ischemia/blood , Oxidative Stress , Rats , Reperfusion/methods
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